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QGIS User Guide - OSGeo Server

1. QGIS 1 1 0 User Guide 97 9 GRASS GIS INTEGRATION Options The tab provides a simplified module dialog where you can usually select a raster or vector layer visualized in the QGIS canvas and enter further module specific parameters to run the module The provided module parameters are often not complete to keep the dialog clear If you want to use further module parameters and flags you need to start the GRASS Shell and run the module in the command line Output The Output tab provides information about the output status of the module When you click the button the module switches to the Output tab and you see information about the analysis process If all works well you will finally see a Successfully finished message Manual The tab shows the HTML help page of the GRASS module You can use it to check further module parameters and flags or to get a deeper knowledge about the purpose of the module At the end of each module manual page you see further links to the Main Help index the Thematic index and the Full index These links provide the same information as if you use the module g manual Tip 40 DISPLAY RESULTS IMMEDIATELY If you want to display your calculation results immediately in your map canvas you can use the View Output button at the bottom of the module tab 9 9 2 Working with the GRASS LOCATION browser Another useful feature inside the GRASS Toolbox is the G
2. Classification field eat Addclass Delete classes Randomize Colors Reset Colors Classification Field cat Iz Style Options Maximum Value Outline Width 0 40 B Draw polygon outline Restore Default Style Jl Save As Default I Load Style Save Style Restore Default Style Jl Save As Default I Load Style Save Style Help o Apy cancel Hep Ek Apply cancel c Continous color d Unique value Style Options Within this dialog you can style your vector layer Depending on the selected rendering option you have the possibility to also classify your mapfeatures QGIS 1 1 0 User Guide 40 5 4 The Vector Properties Dialog At least the following styling options apply for nearly all renderers Outline style pen style for your outline of your feature you can also set this to no pen Outline color color of the ouline of your feature Outline width width of your features Fill color fill color of your features Fill style Style for filling Beside the given brushes you can select Fill style texture Y and click the l button for selecting your own fill style Currently the fileformats jpeg xpm and png are supported Once you have styled your layer you also could save your layer style to a separate file with qm1 ending To do this use the button Save Style No need to say
3. GML Yi and define a path and the vector output QGIS 1 1 0 User Guide 141 12 USING QGIS CORE PLUGINS 12 12 Oracle GeoRaster Plugin In Oracle databases raster data can be stored in SDO_GEORASTER objects available with the Oracle Spatial extension In QGIS the Oracle GeoRaster Plugin is supported by GDAL and depends on Oracle s Database product being installed and working on your machine While Oracle is proprietary software they provide their software free for development and testing purposes Here is one simple example of how to load raster images to GeoRaster gdal_translate of georaster input_file tif geor scott tiger orcl This will load the raster into the default GDAL_IMPORT table as a column named RASTER 12 12 1 Managing connections Firstly the Oracle GeoRaster Plugin must be enabled using the Plugin Manager see Section 11 1 1 The first time you load a GeoRaster in QGIS you must create a connection to the Oracle database that contains the data To do this begin by clicking on the a Select GeoRaster toolbar button it will open the Select Oracle Spatial GeoRaster dialog window Click on to open the dialog window and specify the connection parameters See Figure 60 e Name Enter a name for the database connection e Database instance Enter the name of the database that you will connect to e Username Specify your own username that you wi
4. Plugin makes it possible to export the current map canvas to PDF format quickly and easily with minimal effort The only parameters that need to be specified are a Map Title a Map Name and the Paper Size See Figure 50 If you require additional control over the map layout please use the print composer plugin described in Section 10 Figure 50 Quick Print Dialog amp O QGIS Quick Print Plugin x Quick Print Map Title e g ACME inc Quantum GIS Map Name e g Water Features Quick Print Copyright c QGIS 2008 Page Size a4 210 x 297 mm 8 26 x 11 69 inches Note If you want more control over the map layout please use the map composer function in QGIS ORES Quick Print result as DIN A4 PDF using the alaska sample dataset Quantum GIS Quick Print 04 01 09 Southeast Alaska CAPT TTY is T A j Gg c QGIS 2009 A iisa La QGIS 1 1 0 User Guide 126 12 7 GPS Plugin 12 7 GPS Plugin 12 7 1 What is GPS GPS the Global Positioning System is a satellite based system that allows anyone with a GPS receiver to find their exact position anywhere in the world It is used as an aid in navigation for example in airplanes in boats and by hikers The GPS receiver uses the signals from the satellites to calculate its latitude longitude and sometimes elevation Most receivers also have the capability to store locations known as way
5. Refresh e e Layer amp New Vector Layer amp Add a Vector Layer amp Add a Raster Layer Add a PostGIS Layer Add a WMS Layer Open Attribute Table Z Toggle editing Save As Shapefile Remove Layer Properties ee Add to Overview Add All To Overview amp Hide All Layers Show All Layers Settings Panels Toolbars Save Selection As Shapefile 2 Remove All From Overv Toggle Fullscreen Mode 2 Project Properties Custom CRS see Section 4 8 see Section 4 8 N see Section 5 5 4 v see Section 5 R see Section 6 D see Section 5 2 w see Section 7 2 Ctrl D 8 ew goa see Section 4 5 see Section 8 4 X Map Navigation Xx Map Navigation Xx Map Navigation Xx Map Navigation X Attributes X Attributes X Attributes Xx Map Navigation X Manage Layers X Digitizing X Manage Layers Xx Manage Layers Xx Manage Layers Xx Manage Layers QGIS 1 1 0 User Guide 16 4 2 QGIS GUI Options see Section 4 7 e Plugins Futher menu items are added by plugins as they are loaded 9 Plugin Manager see Section 11 1 Help Help Contents QGIS Home Page w Check QGIS Version 4 2 2 Toolbars The toolbars provide access to most of the same functions as the menus plus additional tools
6. Format for the output image generated by MapServer Web Template Full path to the MapServer template file to be used with the map file Web Header Full path to the MapServer header file to be used with the map file Web Footer Full path to the MapServer footer file to be used with the map file Only the Map file and QGIS project file inputs are required to create a map file however by omitting the other parameters you may end up creating a non functional map file depending on your intended use Although QGIS is good at creating a map file from your project file it may require some tweaking to get the results you want For this example we will create a map file using the project file mapserverproject qgs we just created see Figure 57 1 Start the MapServer dialog see Figure 57 by clicking the MapServer Export icon in the toolbar menu Enter the name e g qgisproject map for your new map file Browse and find the QGIS project file e g mapserverproject qgs you previously saved Enter a name e g MyMap for the map Enter the width and height e g 600 for the width and 400 for the height for your output image For this example the layers are in meters so we change the units to meters Choose png for the image type oOo N OO bh W PD Click to generate the new map file qggisproject map QGIS displays the success of your efforts You can view the map file in any text editor or v
7. QGIS 1 1 0 User Guide 12 4 2 QGIS GUI 2 Vectors Supported formats include ESRI Shapefiles and others supported by OGR and PostgreSQL layers using the PostGIS extension Tip 2 EXAMPLE USING COMMAND LINE ARGUMENTS You can start QGIS by specifying one or more data files on the command line For example assuming you are in the qgis_sample_data directory you could start QGIS with a vector layer and a raster file set to load on startup using the following command qgis raster landcover img gml lakes gml Command line option snapshot This option allows you to create a snapshot in PNG format from the current view This comes in handy when you have a lot of projects and want to generate snapshots from your data Currently it generates a PNG file with 800x600 pixels A filename can be added after snapshot Command line option 1ang Based on your locale QGIS selects the correct localization If you would like to change your language you can specify a language code For example lang it starts QGIS in ital ian localization A list of currently supported languages with language code is provided at http wiki qgis org qgiswiki TranslatorsCorner Command line option project Starting QGIS with an existing project file is also possible Just add the command line option project followed by your project name and QGIS will open with all layers loaded described in the given file Command line option extent To start
8. Quantum GIS User Guide Version 1 1 0 Pan Preamble This document is the original user guide of the described software Quantum GIS The software and hardware described in this document are in most cases registered trademarks and are therefore subject to the legal requirements Quantum GIS is subject to the GNU General Public License Find more information on the Quantum GIS Homepage http qgis osgeo org The details data results etc in this document have been written and verified to the best of knowledge and responsibility of the authors and editors Nevertheless mistakes concerning the content are possible Therefore all data are not liable to any duties or guarantees The authors editors and publishers do not take any responsibility or liability for failures and their consequences Your are always welcome to indicate possible mistakes This document has been typeset with IAT X It is available as IATEX source code via subversion and online as PDF document via http qgis osgeo org documentation manuals html Translated versions of this document can be downloaded via the documentation area of the QGIS project as well For more information about contributing to this document and about translating it please visit http www qgis org wiki Links in this Document This document contains internal and external links Clicking on an internal link moves within the document while clicking on an external link opens an internet
9. If you specify too big of a tolerance QGIS may snap to the wrong vertex especially if you are dealing with a large number of vertices in close proximity Set search radius too small and it won t find anything to move The search radius for vertex edits in layer units can be defined in the Digitizing tab under gt Options The same place where you define the general project wide snapping tolerance 5 5 2 Topological editing Besides layer based snapping options the tab in menu Settings gt Project Properties also provides some topological functionalities In the Digitizing option group you can Enable topological editing and or activate Avoid intersections of new polygons Enable topological editing The option X Enable topological editing is for editing and maintaining common boundaries in poly gon mosaics QGIS detects a shared boundary in a polygon mosaic and you only have to move the vertex once and QGIS will take care about updating the other boundary Avoid intersections of new polygons The second topological option called XJ Avoid intersections of new polygons avoids overlaps in polygon mosaics It is for quicker digitizing of adjacent polygons If you already have one poly gon it is possible with this option to digitise the second one such that both intersect and qgis then cuts the second polygon to the common boundary The advantage is that users
10. In some cases such as the gathering of statistics in raster layers the progress bar will be used to show the status of lengthy operations If a new plugin or a plugin update is available you will see a message in the status bar On the right side of the status bar is a small checkbox which can be used to temporarily prevent layers being rendered to the map view see Section 4 3 below At the far right of the status bar is a projector icon Clicking on this opens the projection properties for the current project Tip 6 CALCULATING THE CORRECT SCALE OF YOUR MAP CANVAS When you start QGIS degrees is the default unit and it tells QGIS that any coordinate in your layer is in degrees To get correct scale values you can either change this to meter manually in the General tab under Settings gt Project Properties or you can select a project Coordinate Reference System CRS clicking on the projector icon in the lower right hand corner of the statusbar In the last case the units are set to what the project projection specifies e g units m 4 3 Rendering By default QGIS renders all visible layers whenever the map canvas must be refreshed The events that trigger a refresh of the map canvas include e Adding a layer e Panning or zooming e Resizing the QGIS window e Changing the visibility of a layer or layers QGIS 1 1 0 User Guide 20 4 3 Rendering QGIS allows you to control the rendering
11. Print Composer opens a dialog where you can layout and print the current map canvas see Section 10 4 7 GUI Options QB Some basic options for QGIS can be selected using the Options dialog Select the menu option Settings gt Options The tabs where you can optmize your options are General Tab x Ask to save project changes when required e x Warn when opening a project file saved with an older version of QGIS 7 x Change Selection and backgroud Color e Change the icon theme choose between default classic gis and nkids e X Capitalise layer names in legend x Display classification attribute names in legend x Hide splash screen at startup e x Open attribute table in a dock window show features in current canvas Rendering Tab x By deafult new layers added to the map should be displayed e Define number of features to draw before updating the display Define attribute table behavior choose between show all features show selected features and x Make lines appear less jagged at the expense of some drawing performance QGIS 1 1 0 User Guide 24 4 7 GUI Options e X Fix problems with incorrectly filled polygons e x Continously redraw when dragging the legend map divider Map tools Tab e Define Search Radius as a percentage
12. VACUUM gis_data t q gsherman madison current 5 3 SpatiaLite Layers amp The first time you load data from a Spatialite database begin by clicking on the e Add SpatiaLite Layer toolbar button or by selecting the Add SpatiaLite Layer option from the Layer menu or by typing L This will bring up a window which will allow you to either connect to a Spatialite database already known to QGIS which you can choose from the dropdown menu or to define a new connection to a new database To define a new connection click on and use the file browser to point to your SpatiaLite database which is a file with a sqlite extension 5 4 The Vector Properties Dialog The Layer Properties dialog for a vector layer provides information about the layer symbology settings and labeling options If your vector layer has been loaded from a PostgreSQL PostGIS datastore you can also alter the underlying SQL for the layer either by hand editing the SQL on the tab or by invoking the Query Builder dialog on the tab To access the Layer Properties dialog double click on a layer in the legend or right click on the layer and select Properties from the popup menu QGIS 1 1 0 User Guide 38 5 4 The Vector Properties Dialog Figure 8 Vector Layer Properties Dialog A 4 Layer Properties General symbology Metadata Labels Actions Attributes r Options Displa
13. Available in CRS The projections that this layer can be rendered in by the WMS server These are listed in the WMS native format Available in style The image styles that this layer can be rendered in by the WMS server 7 2 7 WMS Client Limitations Not all possible WMS Client functionality had been included in this version of QGIS Some of the more notable exceptions follow Editing WMS Layer Settings Once you ve completed the Add WMS layer procedure there is no ability to change the set tings A workaround is to delete the layer completely and start again WMIS Servers Requiring Authentication Currently public accessible and secured WMS services are supported The secured WMS servers can be accessed by public authentification You can add the optional credentials when you add a WMS server See section 7 2 2 for details QGIS 1 1 0 User Guide 75 7 WORKING WITH OGC DATA Tip 30 ACCESSING SECURED OGC LAYERS If you need to access secured layers with other secured methods than basic authentification you could use InteProxy as a transparent proxy which does supports several authentification methods More information can be found at the InteProxy manual found on the website http inteproxy wald intevation org 7 3 WFS Client In QGIS a WFS layer behaves pretty much like any other vector layer You can identify and select features and view the attribute table An exception is that editing is
14. Dialog To view and set the properties for a raster layer double click on the layer name in the map legend or right click on the layer name and choose from the context menu Figure 18 shows the Raster Layer Properties dialog There are several tabs on the dialog e Symbology e Transparency e Colormap General e Metadata e Pyramids iiit e Histogram QGIS 1 1 0 User Guide 63 6 WORKING WITH RASTER DATA Figure 18 Raster Layers Properties Dialog A Raster Layer Properties Transparency Colormap General Metadata Render as Pyramids Histogram Single band gray Three band color _ Invert color map RGB mode band selection and scaling Red band Not Set Green band Not Set Blue band Not Set Custom min max values Red min o Red max Use standard deviation Default R 1 G 2 B 3 Green min 0 Green max Blue min 0 Blue max Note Load min max values from band Contrast enhancement Estimate faster Current No Stretch Actual slower Load Default No Stretch 6 3 1 Symbology Tab QGIS can render raster layers in two different ways Restore Default Style Save As Default Load Style Save Style e Single band one band of the image will be rendered as gray or in pseudocolors Help Apply Cancel e Three band color three bands from the image wil
15. For example you shouldn t have fragments such as request GetCapabilities or version 1 0 0 in your URL 7 2 3 Loading WMS Layers Once you have successfully filled in your parameters you can select the button to retrieve the capabilities of the selected server This includes the Image encoding Layers Layer Styles and Projections Since this is a network operation the speed of the response depends on the quality of your network connection to the WMS server While downloading data from the WMS server the download progress is visualized in the left bottom of the WMS Plugin dialog Your screen should now look a bit like Figure 19 which shows the response provided by the NASA JPL OnEarth WMS server Figure 19 Dialog for adding a WMS server showing its available layers amp Add Layer s from a Server lt keto gt Servers Server Search NASA JPL Delete Add default servers Title Abstract OnEarth Web Map Server lss us_colordem Digital Elevation Map of th The DTED Le us_elevation Digital Elevation Map of th DTED Level us_ned United States elevation 30m Continental uv El wordwind_ dem SRTM derived alobal eleva __A_cilohal A J IEA A Image encoding e JPEG PNG TIFF r Coordinate Reference System WGS 84 Change Image Encoding The Image encoding section now lists the formats that are supported by both the client and server Choose one
16. GDAL_RDT 215 georaster scotttigerorcl GDAL_RDT 216 georaster scott tiger orcl GDAL_RDT 217 georaster scotttigerorcl GDAL_RDT 218 Selection georaster scott tigerorcl GDAL_IMPORT RASTER Update He Cas chose 5 GeoRaster objects on table GDAL_IMPORT column RASTER This is an example using PL SQL cd sqlplus scott tiger SQL gt DECLARE gr sdo_georaster BEGIN SELECT image INTO gr FROM cities WHERE id 1 FOR UPDATE sdo_geor generatePyramid gr rLevel 5 resampling NN UPDATE cities SET image gr WHERE id 1 COMMIT END QGIS 1 1 0 User Guide 144 12 13 Other core plugins 12 13 Other core plugins The remaining core plugins are listed in Table 11 along with references to the chapters in this manual which cover their usage Table 11 Other Core Plugins Icon Plugin Manual Reference D Diagram Overlay Chapter 5 4 7 Y GRASS Chapter 9 and Appendix B E Plugin Installer Chapter 11 1 3 a SPIT Chapter 5 2 4 e WFS Chapter 7 3 QGIS 1 1 0 User Guide 145 13 USING EXTERNAL QGIS PYTHON PLUGINS 13 Using external QGIS Python Plugins External QGIS plugins are written in Python They are stored in either the Official or User con tributed QGIS Repostories or in various other external repositories maintained by individual au thors Table 12 shows a list of curently available Official plugins with a short description Detailed do
17. Guide 101 10 PRINT COMPOSER 10 1 Using Print Composer Before you start to work with the print composer you need to load some raster and vector layers in the QGIS map canvas and adapt their properties to suite your own convinience After everything is rendered and symbolized to your liking you click the al Print Composer icon Figure 35 Print Composer amp QGIS print composer EEE TEETE EKA LSL Mewen mm 7 Width 297 Height 210 Orentaton Landscape v r Snapping Xt Snap to grid Grid resolution Offset x Offset y Pen width Grid color Grid style Print as raster Opening the print composer provides you with a blank canvas to which you can add the current QGIS map canvas legend scalebar images and text Figure 35 shows the initial view of the print composer with an activated Snap to grid modus but before any elements are added The print composer provides two tabs e The tab allows you to set paper size orientation the print quality for the output file in QGIS 1 1 0 User Guide 102 10 1 Using Print Composer dpi and to activate snapping to a grid of a defined resolution Please note the X Snap to grid feature only works if you define a grid resolution gt 0 Furthermore you can also activate the Print as raster checkbox This means all elements will be rastered before printing or saving as Po
18. Load saved projects into a QGIS session using gt Open Project or gt Open Recent Project If you wish to clear your session and start fresh choose gt _ New Project Either of these menu options will prompt you to save the existing project if changes have been made since it was opened or last saved The kinds of information saved in a project file include e Layers added e Layer properties including symbolization e Projection for the map view e Last viewed extent The project file is saved in XML format so it is possible to edit the file outside QGIS if you know what you are doing The file format was updated several times compared to ear lier QGIS versions Project files from older QGIS versions may not work properly anymore To be made aware of this in the tab under Settings s Options you can select Warn when opening a project file saved with an older version of QGIS QGIS 1 1 0 User Guide 23 4 FEATURES AT A GLANCE 4 6 Output There are several ways to generate output from your QGIS session We have discussed one already in Section 4 5 saving as a project file Here is a sampling of other ways to produce output files e Menu option Save as Image opens a file dialog where you select the name path and type of image PNG or JPG format From this release a world file with extension PNGW or JPGW saved in the same folder georeferences the image e Menu option
19. Singleparts to multipart Merge multiple features to a single multipart feature based on a unique ID field Polygons to lines Convert polygons to lines multipart polygons to multiple singlepart lines GB h wa AA Extract nodes Extract nodes from line and polygon layers and output them as points Table 10 fTools Data management tools Data management tools available via the fTools plugin Tool Purpose Export to projection Project features to new CRS and export as new shapefile Define projection Specify the CRS for shapefiles whose CRS has not been defined Join attributes Join additional attributes to vector layer attribute table and output re sults to a new shapefile Additional attributes can be from a vector layer or stand alone dbf table Join attributes by location Join additional attributes to vector layer based on spatial relationship Attributes from one vector layer are appended to the attribute table of another layer and exported as a shapefile Split vector layer Split input layer into multiple separate layers based on input field QGIS 1 1 0 User Guide 133 12 USING QGIS CORE PLUGINS 12 9 Interpolation Plugin The Interplation plugin can be used to generate a TIN or IDW interpolation of a point vector layer It is very simple to handle and provides an intiuitive graphical user interface for creating interpolated raster lay
20. St Vincent 45 British West Indies Grid 2007 8 E TM65 Irish Grid TMAS Irish National Grid idenrecated _ 29900__2455 ly proj tmerc lat_0 53 5 lon_0 8 k 1 000035 x_0 200000 y_0 250000 a 6377340 189 b 6356034 447938534 units m no_defs Search EPSGID C Name Ring TM65 Irish Grid EPSG 29902 WGS 84 EPSG 4326 Unknown datum based upon the WGS 84 ellipsoid EPSG 4030 E Help very Cancel K menu Custom CRS are stored in your QGIS user database In addition to your custom CRS this database also contains your spatial bookmarks and other custom data Defining a custom CRS in QGIS requires a good understanding of the Proj 4 projection library To begin refer to the Cartographic Projection Procedures for the UNIX Environment A User s Man ual by Gerald I Evenden U S Geological Survey Open File Report 90 284 1990 available at ftp ftp remotesensing org proj 0F90 284 pdf This manual describes the use of the proj 4 QGIS 1 1 0 User Guide 82 8 4 Custom Coordinate Reference System Figure 24 Custom CRS Dialog A Custom Coordinate Reference System Definition x Define You can define your own custom Coordinate Reference System CRS here The definition must conform to the proj4 format for specifying a CRS Parameters p rOj tm zone 31 ellps intl units m no_defs Aa D SEO Test Us
21. Starting and Stopping QGIS In Section 3 3 you already learned how to start QGIS We will repeat this here and you will see that QGIS also provides further command line options A Assuming that QGIS is installed in the PATH you can start QGIS by typing qgis at a command prompt or by double clicking on the QGIS application link or shortcut on the desktop P e T Start QGIS using the Start menu or desktop shortcut or double click on a QGIS project file gt X Double click the icon in your Applications folder To stop QGIS click the menu options Q EZ Fite X QGIS gt Quit or use the shortcut Ctrl Q 4 1 1 Command Line Options i QGIS supports a number of options when started from the command line To get a list of the options enter ggis help on the command line The usage statement for QGIS is qgis help Quantum GIS 1 1 0 Pan Unstable Pan Unstable Quantum GIS QGIS is a viewer for spatial data sets including raster and vector data Usage qgis options FILES options snapshot filename emit snapshot of loaded datasets to given file lang language use language for interface text project projectfile load the given QGIS project extent xmin ymin xmax ymax set initial map extent help this text FILES Files specified on the command line can include rasters vectors and QGIS project files qgs 1 Rasters Supported formats include GeoTiff DEM and others supported by GDAL
22. accidentily described QGIS does not support authenficated WFS connections yet Within one of the next releases we expect to also support authenticated WFS servers Meanwhile you could use InteProxy http inteproxy wald intevation org for accessing authenticated WFS servers QGIS 1 1 0 User Guide 78 8 Working with Projections QGIS allows users to define a global and project wide CRS Coordinate Reference System for layers without a pre defined CRS It also allows the user to define custom coordinate reference systems and supports on the fly OTF projection of vector layers All these features allow the user to display layers with different CRS and have them overlay properly 8 1 Overview of Projection Support QGIS has support for approximately 2 700 known CRS Definitions for each of these CRS are stored in a SQLite database that is installed with QGIS Normally you do not need to manipulate the database directly In fact doing so may cause projection support to fail Custom CRS are stored in a user database See Section 8 4 for information on managing your custom coordinate reference systems The CRS available in QGIS are based on those defined by EPSG and are largely abstracted from the spatial_references table in PostGIS version 1 x The EPSG identifiers are present in the database and can be used to specify a CRS in QGIS In order to use OTF projection your data must contain information about its coordinate
23. address In PDF form internal links are shown in blue while external links are shown in red and are handled by the system browser In HTML form the browser displays and handles both identically User Installation and Coding Guide Authors and Editors Tara Athan Radim Blazek Godofredo Contreras Claudia A Engel Otto Dassau Martin Dobias Jurgen E Fischer Anne Ghisla Stephan Holl Marco Hugentobler Magnus Homann Tim Sutton Lars Luthman Gavin Macaulay Werner Macho Carson J Q Farmer Tyler Mitchell Brendan Morely Gary E Sherman David Willis With thanks to Tisham Dhar for preparing the initial msys MS Windows environment documentation to Tom Elwertowski and William Kyngesburye for help in the MAC OSX Installation Section and to Carlos Davila Paolo Cavallini and Christian Gunning for revisions If we have neglected to mention any contributors please accept our apologies for this oversight Copyright 2004 2009 Quantum GIS Development Team Internet http qgis osgeo org Contents Contents Title i Preamble ii Table of Contents iii List of Figures viii List of Tables X List of QGIS Tips xi 1 Foreword 1 1 1 FRAUMES oec cacos a aeoea ke aor a ae EOR a S E E aTa WU a ee 1 1 SONANDO oi sd BRERA A a di Ga aa RD 4 2 Introduction To GIS 6 EL Why ib althis s0 Dew c coco be ete A A a di A REE E 6 21i E AITANA 7 2 1 2 Vector Data ccc ee asma aa a aa 7 3 Getting Started 9 3 1 Installation 2 2 2 0 02 2 9 de ample Da
24. an entity This often involves the use of a geographic coordinate like a latitude or longitude value Spatial data is another commonly used term as are geographic data GIS data map data location data coordinate data and spatial geometry data Applications using geospatial data perform a variety of functions Map production is the most easily understood function of geospatial applications Mapping programs take geospatial data and render it in a form that is viewable usually on a computer screen or printed page Applications can present static maps a simple image or dynamic maps that are customised by the person viewing the map through a desktop program or a web page Many people mistakenly assume that geospatial applications just produce maps but geospatial data analysis is another primary function of geospatial applications Some typical types of analysis include computing 1 distances between geographic locations the amount of area e g square meters within a certain geographic region what geographic features overlap other features the amount of overlap between features the number of locations within a certain distance of another oOo a A W PY and so on These may seem simplistic but can be applied in all sorts of ways across many disciplines The re sults of analysis may be shown on a map but are often tabulated into a reportto support management decisions The recent phenomena of location based services pro
25. be edited Vertices can be directly edited that is you don t have to choose which feature to edit before you can change its geometry In some cases several features may share the same vertex and so the following rules apply when the mouse is pressed down near map features e Lines The nearest line to the mouse position is used as the target feature Then for moving and deleting a vertex the nearest vertex on that line is the editing target e Polygons If the mouse is inside a polygon then it is the target feature otherwise the nearest polygon is used Then for moving and deleting a vertex the nearest vertex on that polygon is the editing target You will need to set the property Settings gt Options Digitizing gt Search Radius 10 to a number greater than zero Otherwise QGIS will not be able to tell which feature is being edited Adding Vertices of a Feature You can add new vertices to a feature by using the Add Vertex icon on the toolbar Note it doesn t make sense to add more vertices to a Point feature In this version of QGIS vertices can only be added to an existing line segment of a line feature If you want to extend a line beyond its end you will need to move the terminating vertex first then add a new vertex where the terminus used to be Moving Vertices of a Feature You can move vertices using the Move Vertex icon on the toolbar Deleting V
26. close to the marker To fix this we can use the options on the entry Here we can add offsets for the X and Y directions Adding an X offset of 5 will move our labels off the marker and make them more readable Of course if your marker symbol or font is larger more of an offset will be required The last adjustment we ll make is to the labels This just means putting a backdrop around them to make them stand out better To buffer the lakes labels 1 Click the Buffer tab 2 Click the XJ Buffer Labels checkbox to enable buffering 3 Choose a size for the buffer using the spin box 4 Choose a color by clicking on and choosing your favorite from the color selector You can also set some transparency for the buffer if you prefer QGIS 1 1 0 User Guide 42 5 4 The Vector Properties Dialog 5 Click Apply to see if you like the changes If you aren t happy with the results tweak the settings and then test again by clicking Apply A buffer of 1 points seems to give a good result Notice you can also specify the buffer size in map units if that works out better for you The remaining entries inside the tab allow you control the appearance of the labels using attributes stored in the layer The entries beginning with Data defined allow you to set all the parameters for the labels using fields in the layer Not that the tab provides a preview box where your selected label is shown 5 4 5 Actions
27. coordinates or measure features At this time only shapefiles can be created In a future version of QGIS creation of any OGR or PostgreSQL layer type will be supported Creation of GRASS layers is supported within the GRASS plugin Please refer to section 9 6 for more information on creating GRASS vector layers To complete the creation of the new layer add the desired attributes by clicking on the but ton and specifying a name and type for the attribute Only Type real Y Type integer Y and Type string Y attributes are supported Once you are happy with the attributes click and provide a name for the shapefile QGIS will automatically add a shp extension to the name you specify Once the layer has been created it will be added to the map and you can edit it in the same way as described in Section 5 5 3 above 5 5 5 Working with the Attribute Table To open the attribute table for a vector layer make the layer active by clicking on it in the Map legend area Then use Layer from the main menu and and choose Open Attribute Table from QGIS 1 1 0 User Guide 58 5 5 Editing Figure 15 Creating a New Vector Dialog A New Vector Layer File format ESRI Shapefile Type e Point e gt Polygon Attributes Name Name Type String Type Real the menu It is also possible to ri
28. database tables are linked to geometry elements using a category value Category key ID is an integer attached to geometry primitives and it is used as the link to one key column in the database table Tip 35 LEARNING THE GRASS VECTOR MODEL The best way to learn the GRASS vector model and its capabilities is to download one of the many GRASS tutorials where the vector model is described more deeply See http grass osgeo org gdp manuals php for more information books and tutorials in several languages 9 6 Creating a new GRASS vector layer To create a new GRASS vector layer with the GRASS plugin click the Cu Create new GRASS vector toolbar icon Enter a name in the text box and you can start digi tizing point line or polygone geometries following the procedure described in Section 9 7 SAlthough it is possible to mix geometry elements it is unusual and even in GRASS only used in special cases such as vector network analysis Normally you should prefere to store different geometry elements in different layers QGIS 1 1 0 User Guide 91 9 GRASS GIS INTEGRATION In GRASS it is possible to organize all sort of geometry types point line and area in one layer because GRASS uses a topological vector model so you don t need to select the geometry type when creating a new GRASS vector This is different from Shapefile creation with QGIS because Shapefiles use the Simple Feature vector model
29. description file and create a new location based on it m cogo A simple utility for converting bearing and distance measurements to coordinates and vice versa It assumes a cartesian coordinate system QGIS 1 1 0 User Guide 158 B 4 GRASS Toolbox raster data modules B 4 GRASS Toolbox raster data modules This Section lists all graphical dialogs in the GRASS Toolbox to work with and analyse raster data in a currently selected GRASS location and mapset Table 19 GRASS Toolbox Develop raster map modules Develop raster map modules in the GRASS Toolbox Module name Purpose r compress Compresses and decompresses raster maps r region region Sets the boundary definitions to current or default region r region raster Sets the boundary definitions from existent raster map r region vector Sets the boundary definitions from existent vector map r region edge Sets the boundary definitions by edge n s e w r region alignTo Sets region to align to a raster map r null val Transform cells with value in null cells r null to Transform null cells in value cells r quant This routine produces the quantization file for a floating point map r resamp stats Resamples raster map layers using aggregation r resamp interp Resamples raster map layers using interpolation r resample GRASS raster map layer data resampling capability Before you must set ne
30. don t have to digitize all vertices of the common boundary 5 5 3 Editing an Existing Layer By default QGIS loads layers read only This is a safeguard to avoid accidentally editing a layer if there is a slip of the mouse However you can choose to edit any layer as long as the data provider supports it and the underlying data source is writable i e its files are not read only Layer editing is most versatile when used on PostgreSQL PostGIS data sources QGIS 1 1 0 User Guide 51 5 WORKING WITH VECTOR DATA Tip 13 DATA INTEGRITY It is always a good idea to back up your data source before you start editing While the authors of QGIS have made every effort to preserve the integrity of your data we offer no warranty in this regard Tip 14 MANIPULATING ATTRIBUTE DATA Currently only PostGIS layers are supported for adding or dropping attribute columns within this dialog In future versions of QGIS other datasources will be supported because this feature was recently implemented in GDAL OGR gt 1 6 0 All editing sessions start by choosing the lt Toggle editing option This can be found in the con text menu after right clicking on the legend entry for that layer Alternately you can use the Toggle editing button from the toolbar to start or stop the editing mode Once the layer is in edit mode markers will appear at the vertices and additional tool buttons on the editing toolbar will be come av
31. e Name of a Class NewLayer e Method classFactory e Server myhost de e User Text qgis help Code is indicated by a fixed width font PROJCS NAD_1927_Albers GEOGCS GCS_North_American_1927 Platform specific instructions M GUI sequences and small amounts of text can be formatted inline Click A ET File X QGIS gt Quit to close QGIS This indicates that on Linux Unix and Windows platforms click the File menu option first then Quit from the dropdown menu while on Macintosh OSX platforms click the QGIS menu option first then Quit from the dropdown menu Larger amounts of text may be formatted as a list e Lodo this e my do that e X do something else or as paragraphs A X Do this and this and this Then do this and this and this and this and this and this and this and this and this M ig Do that Then do that and that and that and that and that and that and that and that and that and that and that and that and that and that and that Screenshots that appear throughout the user guide have been created on different platforms the platform is indicated by the platform specific icons at the end of the figure caption QGIS 1 1 0 User Guide 5 2 INTRODUCTION TO GIS 2 Introduction To GIS A Geographical Information System GIS 1 is a collection of software that allows you to create visualize query and analyze geospatial data Geospatial data refers to information about the geo graphic location of
32. e Oracle Spatial e PostgreSQL e SDTS e SQLite e UK NTF e U S Census TIGER Line e VRT Virtual Datasource e X Plane Flighgear aeronautical data A 2 GDAL Raster Formats At the date of this document the following formats are supported by the GDAL library 3 A complete is also available at http www gdal org formats_list html e Arc Info ASCII Grid e ADRG ARC Digitilized Raster Graphics e Arc Info Binary Grid adf e Magellan BLX Topo blx xlb e Microsoft Windows Device Independent Bitmap bmp e BSB Nautical Chart Format kap e VTP Binary Terrain Format bt e CEOS Spot for instance e First Generation USGS DOQ doq e New Labelled USGS DOQ doq e Military Elevation Data dt0 dt1 e ERMapper Compressed Wavelets ecw e ESRI hdr Labelled e ENVI hdr Labelled Raster e Envisat Image Product n1 e EOSAT FAST Format e FITS fits 12QGIS implements its own PostgreSQL functions OGR should be built without PostgreSQL support QGIS 1 1 0 User Guide 151 A SUPPORTED DATA FORMATS e Graphics Interchange Format gif e GMT compatible netCDF e GRASS Rasters 3 e Golden Software Binary Grid e TIFF BigTIFF GeoTIFF tif e Hierarchical Data Format Release 4 HDF4 e Hierarchical Data Format Release 5 HDF5 e ILWIS Raster Map mpr mpl e Intergraph Raster e Erdas Imagine img e Atlantis MFF2e e Japanese DEM mem e JPEG JFIF jpg e JPEG2000 jp2 j2
33. extension and resolution The current GRASS region is stored in the LOCATION MAPSET WIND file and it defines north south east and west bounds number of columns and rows horizontal and vertical spatial resolution It is possible to switch on off the visualization of the GRASS region in the QGIS canvas using the Display current GRASS region button With the Edit current GRASS region icon you can open a dialog to change the current region and the symbology of the GRASS region rectangle in the QGIS canvas Type in the new region bounds and resolution and click It also allows to select a new region interactively with your mouse on the QGIS canvas Therefore click with the left mouse button in the QGIS canvas open a rectangle close it using the left mouse button again and click The GRASS module g region provide a lot more parameters to define an appropriate region extend and resolution for your raster analysis You can use these parameters with the GRASS Toolbox described in Section 9 9 9 9 The GRASS toolbox The Open GRASS Tools box provides GRASS module functionalities to work with data inside a selected GRASS LOCATION and MAPSET To use the GRASS toolbox you need to open a LOCATION and MAPSET where you have write permission usually granted if you created the MAPSET This is necessary because new raster or vector layers created during analysis need to be written to the currently selected LOCATION an
34. if you have one that does not work with any of the device types listed in the Download from GPS and Upload to GPS tools you can define your own device type for it You do this by using the GPS device editor which you start by clicking the Edit devices button in the download or the upload tabs To define a new device you simply click the button enter a name a download com mand and an upload command for your device and click the Update device button The name QGIS 1 1 0 User Guide 129 12 USING QGIS CORE PLUGINS will be listed in the device menus in the upload and download windows and can be any string The download command is the command that is used to download data from the device to a GPX file This will probably be a GPSBabel command but you can use any other command line program that can create a GPX file QGIS will replace the keywords type Zin and Zout when it runs the command type will be replaced by w if you are downloading waypoints r if you are downloading routes and t if you are downloading tracks These are command line options that tell GPSBabel which feature type to download Zin will be replaced by the port name that you choose in the download window and out will be replaced by the name you choose for the GPX file that the downloaded data should be stored in So if you create a device type with the download command gpsbabel type i garmin o gpx in out
35. opacity fill and outline color 10 Also load the other two vector layers rivers and airports and adapt their properties As you see it is very simple to load GRASS raster and vector layers in QGIS See following Sections for editing GRASS data and creating a new LOCATION More sample GRASS LOCATIONs are available at the GRASS website at http grass osgeo org download data php Tip 34 GRASS DATA LOADING If you have problems loading data or QGIS terminates abnormally check to make sure you have loaded the GRASS plugin properly as described in Section 9 1 QGIS 1 1 0 User Guide 86 9 3 GRASS LOCATION and MAPSET 9 3 GRASS LOCATION and MAPSET GRASS data are stored in a directory referred to as GISDBASE This directory often called grassdata must be created before you start working with the GRASS plugin in QGIS Within this directory the GRASS GIS data are organized by projects stored in subdirectories called LOCATION Each LOCATION is defined by its coordinate system map projection and geographical boundaries Each LOCATION can have several MAPSETs subdirectories of the LOCATION that are used to subdivide the project into different topics subregions or as workspaces for individual team members Neteler amp Mitasova 2008 2 In order to analyze vector and raster layers with GRASS modules you must import them into a GRASS LOCATION 4 Figure 25 GRASS data in the alaska LOCATION adapted from Neteler amp Mit
36. parameters 70 layers 71 limits 75 coordinate reference system 72 CRS 72 GetFeaturelnfo 74 identify 74 image encoding 72 layer settings editing 75 layer transparency 72 metadata 74 properties 74 remote server authentication 75 basic authentification 75 layer ordering 72 selection 70 URL 71 search 73 secured layers 76 serversearch 73 URL 70 zoom mouse wheel 19 QGIS 1 1 0 User Guide 179
37. range is specifed by minimum maximum value and a step width e g 0 360 10 in the value column of the Attributes tab e file name the line edit widget is accompanied by a push button When pressed it allows to select a filename using the standard file dialog 5 4 7 Diagram Tab The tab allows you to add a grahic overlay to a vector layer To activate this feature open the Plugin Manager and select the Diagram Overlay plugin After this there is a new tab in the vector Layer Properties dialog where the settings for diagrams may be entered see figure 11 The current implementation of diagrams provides support for pie and barcharts and for linear scaling QGIS 1 1 0 User Guide 47 5 WORKING WITH VECTOR DATA Figure 11 Vector properties dialog with diagram tab amp Layer Properties General Symbology l Metadata Labels Actions Attributes Diagram Overlay X Display diagrams Diagram type Attributes Bar chart D Add attribute Remove attribute Attribute Color Classification type Classification attribute Scale linearly between O and the following attribute value diagram size linearly scaling TE JUL find maximum Value 63 Size 15 S Size unit Millimeter Restore Default Style Save As Default Load Style Save Style Help
38. that Load Style loads your saved layer style file If you wish to always use a particular style whenever the layer is loaded use the Save As Default button to make your style the default Also if you make changes to the style that you are not happy with use the Restore Default Styel button to revert to your default style Vector transparency QGIS 1 1 0 allows to set a transparency for every vector layer This can be done with the slider Transparency 0 Y inside the symbology tab see fig 8 This is very useful for overlaying several vector layers 5 4 3 Metadata Tab The tab contains information about the layer including specifics about the type and location number of features feature type and the editing capabilities The Layer Spatial Reference System section providing projection information and the Attribute field info section listing fields and their data types are displayed on this tab This is a quick way to get information about the layer 5 4 4 Labels Tab The tab allows you to enable labeling features and control a number of options related to fonts placement style alignment and buffering We will illustrate this by labelling the lakes shapefile of the qgis_example_dataset 1 Load the Shapefile alaska shp and GML file lakes gm1 in QGIS 2 Zoom in a bit to your favorite area with some lake QGIS 1 1 0 User Guide 41 5 WORKING WITH VECTOR DATA 3 M
39. the arrow should be oriented For placement of the arrow you have four options corresponding to the four corners of the map canvas Figure 45 North Arrow Plugin A North Arrow Plugin Properties a Angle ED o E Placement Bottom Left 4 y Enable North Arrow v Set direction automatically aSa Help cance 12 3 3 Scale Bar Plugin The Scale Bar plugin adds a simple scale bar to the map canvas You control the style and placement as well as the labeling of the bar QGIS only supports displaying the scale in the same units as your map frame So if the units of your layers are in meters you can t create a scale bar in feet Likewise if you are using decimal degrees you can t create a scale bar to display distance in meters To add a scale bar 1 Click on gt gt or use the Scale Bar button from the Toolbar 2 Choose the placement from the Placement Bottom Left Y drop down list QGIS 1 1 0 User Guide 119 12 USING QGIS CORE PLUGINS wm h Choose the style from the Scale bar style Tick Down Y list Select the color for the bar Color of bar ISO or use the default black color 5 Set the size of the bar and its label Size of bar 30 degrees 6 Make sure the Enable scale bar checkbox is checked 7 Optionally choose to automatically sn
40. these field values to a text file for the selected record shown in yellow in the QGIS map area Here is the action to achieve this bash c echo taxon_name flat long gt gt tmp species_localities txt After selecting a few localities and running the action on each one opening the output file will show something like this QGIS 1 1 0 User Guide 44 5 4 The Vector Properties Dialog Acacia mearnsii 34 0800000000 150 0800000000 Acacia mearnsii 34 9000000000 150 1200000000 Acacia mearnsii 35 2200000000 149 9300000000 Acacia mearnsii 32 2700000000 150 4100000000 As an exercise we create an action that does a Google search on the lakes layer First we need to determine the URL needed to perform a search on a keyword This is easily done by just going to Google and doing a simple search then grabbing the URL from the address bar in your browser From this little effort we see that the format is http google com search q qgis where qgis is the search term Armed with this information we can proceed 1 Make sure the lakes layer is loaded 2 Open the Layer Properties dialog by double clicking on the layer in the legend or right click and choose Properties from the popup menu 3 Click on the Actions tab 4 Enter a name for the action for example Google Search 5 For the action we need to provide the name of the external program to run In this case we can use Firefox If the program is n
41. to the map but its visibility checkbox in the legend will be unchecked by default To set this option choose menu option Settings gt Options and click on the tab Uncheck the By default new layers added to the map should be displayed checkbox Any layer added to the map will be off invisible by default QGIS 1 1 0 User Guide 21 4 FEATURES AT A GLANCE c Updating the Map Display During Rendering You can set an option to update the map display as features are drawn By default QGIS does not display any features for a layer until the entire layer has been rendered To update the display as features are read from the datastore choose menu option Settings gt Options click on the tab Set the feature countto an appropriate value to update the display during rendering Setting a value of O disables update during drawing this is the default Setting a value too low will result in poor performance as the map canvas is continually updated during the reading of the features A suggested value to start with is 500 d Influence Rendering Quality To influence the rendering quality of the map you have 3 options Choose menu option Settings gt click on the tab and select or deselect following checkboxes x Make lines appear less jagged at the expense of some drawing performance e X Fix problems with incorrectly filled polygons x Continuously redraw the map wh
42. toolbar bar button or type v change the file type filter to Files of Type OGR Maplnfo mif tab MIF TAB Y and select the layer you want to load 5 1 4 Loading an Arcinfo Binary Coverage To load an Arcinfo binary coverage click on the or type to open the Add Vector Layer dialog Add a vector layer Select Directory toolbar button Change to Type Arc Ingo Binary Coverage Y Navigate to the directory that contains the coverage files and QGIS 1 1 0 User Guide 31 5 WORKING WITH VECTOR DATA Figure 7 QGIS with Shapefile of Alaska loaded amp y Quantum GIS 1 0 0 Kore File Edit View Layer Settings Plugins Help ARBA SRRA GARRO 4 1 2109 gt Mirza o RR vr CAARAXAQAO Legend EJES 2 E alaska E S 242188 1496368 Scale 152342778358 09 x Render E select it Similarly you can load directory based vector files in the UK National Transfer Format as well as the raw TIGER Format of the US Census Bureau 5 2 PostGIS Layers PostGIS layers are stored in a PostgreSQL database The advantages of PostGIS are the spatial indexing filtering and query capabilities it provides Using PostGIS vector functions such as select and identify work more accurately than with OGR layers in QGIS To use PostGIS layers you must e Create a stored connection in QGIS to the PostgreSQL datab
43. where you can find a variety of useful information relating to QGIS development release plans links to download sites message translation hints and so on Check it out there are some goodies inside QGIS 1 1 0 User Guide 149 A SUPPORTED DATA FORMATS A Supported Data Formats QGIS uses the GDAL OGR library to read and write vector and raster data formats Note that not all of the format listed below may work in QGIS for various reasons For example some require external commercial libraries or the GDAL installation of your OS was not build to support the format you want to use Only those formats that have been well tested will appear in the list of file types when loading a vector or raster into QGIS Other untested formats can be loaded by selecting A 1 OGR Vector Formats At the date of this document the following formats are supported by the OGR library 5 A complete is also available at http www gdal org ogr ogr_formats html e Arc Info Binary Coverage e Comma Separated Value csv e DODS OPeNDAP e ESRI Personal GeoDatabase e ESRI ArcSDE e ESRI Shapefile e FMEObjects Gateway e GeoJSON e Geoconcept Export e GeoRSS e GML e GMT e GPX e GRASS Vector 1 e Informix DataBlade e INTERLIS e IHO S 57 ENC e Mapinfo File e Microstation DGN e OGDI Vectors GRASS support is supplied by the QGIS GRASS data provider plugin QGIS 1 1 0 User Guide 150 A 2 GDAL Raster Formats e ODBC
44. with a specific map extent use this option You need to add the bounding box of your extent in the following order separated by a comma extent xmin ymin xmax ymax 4 2 QGIS GUI When QGIS starts you are presented with the GUI as shown below the numbers 1 through 6 in yellow ovals refer to the six major areas of the interface as discussed below Note Your window decorations title bar etc may appear different depending on your operating system and window manager QGIS 1 1 0 User Guide 13 4 FEATURES AT A GLANCE Figure 2 QGIS GUI with Alaska sample data amp Quantum GIS 1 1 0 Pan Unstable 5 HRS railroads E landcover The QGIS GUI is divided into six areas 1 Menu Bar 4 Map View 2 Tool Bar 5 Map Overview 3 Map Legend 6 Status Bar These six components of the QGIS interface are described in more detail in the following sections 4 2 1 Menu Bar The menu bar provides access to various QGIS features using a standard hierarchical menu The top level menus and a summary of some of the menu options are listed below together with the icons of the corresponding tools as they appear on the toolbar as well as keyboard shortcuts Although QGIS 1 1 0 User Guide 14 4 2 QGIS GUI most menu options have a corresponding tool and vice versa the menus are not organized quite like the toolbars The toolbar containing the tool is listed after each menu option as a checkbox entry For more inform
45. wrote it Thus it is not the intent of this section to claim rights or contest your rights to work written entirely by you rather the intent is to exercise the right to control the distribution of derivative or collective works based on the Program In addition mere aggregation of another work not based on the Program with the Program or with a work based on the Program on a volume of a storage or distribution medium does not bring the other work under QGIS 1 1 0 User Guide 170 the scope of this License 3 You may copy and distribute the Program or a work based on it under Section 2 in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following a Accompany it with the complete corresponding machine readable source code which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange or b Accompany it with a written offer valid for at least three years to give any third party for a charge no more than your cost of physically performing source distribution a complete machine readable copy of the corre sponding source code to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange or c Accompany it with the information you received as to the offer to distribute corresponding source code This alternative is allowed only for noncommercial distrib
46. 2 5 Using the Identify Tool Once you have added a WMS server and if any layer from a WMS server is queryable you can then use the YP Identify tool to select a pixel on the map canvas A query is made to the WMS server for each selection made The results of the query are returned in plain text The formatting of this text is dependent on the particular WMS server used 7 2 6 Viewing Properties Once you have added a WMS server you can view its properties by right clicking on it in the legend and selecting i Metadata Tab The Metadata tab displays a wealth of information about the WMS server generally collected from the Capabilities statement returned from that server Many definitions can be gleaned by reading the WMS standards 7 8 but here are a few handy definitions e Server Properties WMS Version The WMS version supported by the server Image Formats The list of MIME types the server can respond with when drawing the map QGIS supports whatever formats the underlying Qt libraries were built with which is typically at least image png and image jpeg Identity Formats The list of MIME types the server can respond with when you use the Identify tool Currently QGIS supports the text plain type e Layer Properties Selected Whether or not this layer was selected when its server was added to this project Visible Whether or not this layer is selected as visible in the lege
47. 23 1 at Label FU oe kee eee ee wee ee ewe Dew ere we a 12 3 2 North Arrow Plugin 12 3 3 Scale Bar Plugin 12 4 Dxf2Shp Converter Plugin 12 5 Georeferencer Plugin 12 6 Quick Print Plugin 12 7 GPS Plugin 12 7 1 What is GPS 12 7 2 Loading GPS data from a file a aa aaa eS Ea ES 12 7 3 GPSBabel 12 7 4 Importing GPS data 12 7 5 Downloading GPS data from a device o o e 12 7 6 Uploading GPS data to a device o o eee 12 7 7 Defining new device 12 8 fTools Plugin 12 9 Interpolation Plugin 12 1 MapServer Export Plugin 12 10 1Creating the Project OR oo ok eb eR OE ee ee ee File G4 te ite a ee Baa SS ee SE oe oS 12 10 2Creating the Map File 22s se eee Gh SG A a A ESS 12 10 3Testing the Map File 12 110GR Converter Plugin 12 120racle GeoRaster Plugin 101 102 103 104 105 106 107 108 109 109 109 110 110 113 114 115 117 118 118 119 119 121 122 126 127 127 127 127 128 128 129 129 131 134 136 136 137 139 140 142 QGIS 1 1 0 User Guide vi Contents 12 12 1Managing connections 6g Sha eRe ES ERLE OSS EESS BEE 142 12 12 2Selecting a GeoRaster o eee ee ee eS 142 12 12 3Displaying GeoRasier lt 2 684486 ee ee eee Re ee ES 143 Ve ther care PUJINE so oe Pe ee ek he ee es eS eee eee 145 13 Using external QGIS Python Plugins 146 14 Help and Support 147 14 1 Mailinglists lt a oe See ae
48. 45406045 258244 57 22 CHANGING THE LAYER DEFINITION ooon a e 60 23 VIEWING A SINGLE BAND OF A MULTIBAND RASTER 65 24 GATHERING RASTER STATISTICS e a ee ee 68 25 ON WMS SERVER URLS 2 ccc en ee bee ba he ada a a i ees 71 26 IMAGE ENGODING se ra a a 4584 4464 640 4 OM SS OE ewe a 72 27 WMS LAYER ORDERING 72 28 WMS LAYER TRANSPARENCY 2 605 ea ee ee ee ee ee 72 29 WMS PROJECTIONS 4 2 2600 64 eee be a ee 73 30 ACCESSING SECURED OGC LAYERS e a 76 31 FINDING WES SERVERS ooo caia bene ee be be ee a we eS 77 32 ACCESSING SECURE WFS SERVERS 78 39 PROJECT PROPERTIES DIALOG cac erioa rekne ee eR a ee 81 94 GRASS DATA LOADING 4 6445 6 Se bw ee ee ee ees 86 35 LEARNING THE GRASS VECTOR MODEL 0 0 00 eee eee a 91 36 CREATING AN ATTRIBUTE TABLE FOR ANEW GRASS VECTORLAYER 92 37 DIGITIZING POLYGONES IN GRASS 0 0 00000 eee ee 92 38 CREATING AN ADDITIONAL GRASS LAYER WITH QGIS 93 39 GRASS EDIT PERMISSIONS 0 0 4 64 0 eee we eee ee es 95 40 DISPLAY RESULTS IMMEDIATELY 2 0 ee a e 98 QGIS 1 1 0 User Guide xi QGIS Tips 41 42 43 44 45 CRASHING PLUGINS lt lt o oaci S44 be Ste Dh eed Re eRe EO aa eg 109 USING EXPERIMENTAL PLUGINS ee 113 PLUGINS SETTINGS SAVED TO PROJECT caca rosaa nerra ro piama 114 CHOOSING THE RESAMPLING METHOD 125 ADD MO
49. 9 For this procedure you have two options a Click on a point in the raster map and enter the X and Y coordinates manually b Click on a point in the raster map and choose the button from map canvas to add the X and Y coordinates with the help of a georeferenced map already loaded in QGIS 3 Continue entering points You should have at least 4 points and the more coordinates you can provide the better the result will be There are additional tools on the plugin dialog to zoom and QGIS 1 1 0 User Guide 122 12 5 Georeferencer Plugin Figure 48 Georeferencer Plugin Dialog A Reference points RRE Edo Transform type Thin plate spline TPS World file spearfish_topo24 modifiedwid Create Create and load layer Load GCPs Save GCPs Close pan the working area in order to locate a relevant set of GCP points The points that are added to the map will be stored in a separate text file filename points which is stored together with the raster image This allows us to reopen the Georeferencer plugin at a later date and add new points or delete existing ones to optimize the result The points file contains values of the form mapX mapY pixelX pixelY You can also Load GCPs and Save GCPs to different directories if you like Choosing the transformation After you have added your GCPs to the raster image you need to select the transformat
50. AUTHORITY EPSG 6267 PRIMEM Greenwich 0 AUTHORITY EPSG 8901 7 UNIT degree 0 0174532925199433 AUTHORITY EPSG 9108 AUTHORITY EPSG 4267 PROJECTION Albers_Conic_Equal_Area PARAMETER standard_parallel_1 55 PARAMETER standard_parallel_2 65 PARAMETER latitude_of_center 50 PARAMETER longitude_of_center 154 PARAMETER false_easting 0 PARAMETER false_northing 0 UNIT us_survey_feet 0 3048006096012192 If you intend to use QGIS as graphical frontend for GRASS you can find a selection of sample locations e g Spearfish or South Dakota at the official GRASS GIS website http grass osgeo org download data php 3 3 Sample Session Now that you have QGIS installed and a sample dataset available we would like to demonstrate a short and simple QGIS sample session We will visualize a raster and a vector layer We will use the landcover raster layer qgis_sample_data raster landcover img and the lakes vector layer qgis_sample_data gml lakes gml start QGIS A Start QGIS by typing qgis at a command prompt M e 7 Start QGIS using the Start menu or desktop shortcut or double click on a QGIS project file X Double click the icon in your Applications folder Load raster and vector layers from the sample dataset 1 Click on the ry Load Raster icon QGIS 1 1 0 User Guide 10 3 3 Sample Session 2 Browse to the folder qgis_sample_data raster select
51. Apply Cancel of the diagram size according to a classification attribute We will demonstrate an example and overlay the alaska boundary layer a barchart diagramm showing some temperature data from a climate vector layer Both vector layers are part of the QGIS sample dataset see Section 3 2 1 First click on the Load Vector icon browse to the QGIS sample dataset folder and load the two vector shape layers alaska shp and climate shp 2 Double click the climate layer in the map legend to open the Layer Properties dialog 3 Click on the Diagram Overlay and select as Diagram type 4 In the diagram we want to display the values of the three columns T_F_JAN T_F_JAN and T_ F_MEAN First select T_F_JAN as Attributes and click Add attribute then T_F_JUL and finally T_F_MEAN 5 For linear scaling of the diagram size we define T_F_JUL as classification attribute QGIS 1 1 0 User Guide 48 5 5 Editing 6 Now click on find maximum value choose a size value and unit and click Apply to display the diagram in the QGIS main window 7 You can now adapt the chart size or change the attribute colors double clicking on the color values in the attribute field Figure 12 gives an impression 8 Finally click Figure 12 Diagram from temperature data overlayed on a map A Quantum GIS 1 1 0 Pan Unstable File Edit View Layer Settings Plugins Tools Help j aeaseePe
52. Boe SEES OSs CL Se eS OES RRS wee A 147 Mes cerdas ee ee ee a Be ee a ee oe R 148 14 3 Buglrackef cc 60S 6 SPREE EHS SHEE SED SESS HERES SAR GREE SE EEE 148 A Blog ss ts isos IAEA a AA a amp E 149 TAS WIK S566 24 2 EO ore hk oS eS SB ee ee hes 149 A Supported Data Formats 150 Pl SOG Vector FOS gt o 6 62448 aaua 2 be A DEANE OE EAE dc 150 A2 DAL Raster Format 2 64 20 ae A Ge ERE AOA OS DEAS 151 B GRASS Toolbox modules 154 B 1 GRASS Toolbox data import and export modules o o o o o 154 B 2 GRASS Toolbox data type conversion modules o o o oo o 157 B 3 GRASS Toolbox region and projection configuration modules 158 B 4 GRASS Toolbox raster data modules o o e 159 B 5 GRASS Toolbox vector data modules o e 163 B 6 GRASS Toolbox imagery data modules o oo eee 166 B 7 GRASS Toolbox database modules o o e 167 B 8 GRASS Toolbox 3D modules 5 5 4 08 Sa cerdas ca a ee a de 168 B 9 GRASS Toolbox help modules 24440442408 is 4 eb eRe a ee es 168 C GNU General Public License 169 C 1 Quantum GIS Qt exception for GPL 2 4 24 0 62h ish be e 54 446 ABS We oS 174 Cited literature 175 Index 176 QGIS 1 1 0 User Guide vil List of Figures List of Figures 1 A Simple QGIS Session O II 11 2 QGIS GUI with Alaska sample data Do ao ere 14 3 Measure tools in action oaaae oo 23 4
53. ECT command supports only outgoing TCP connections supports authentication HttpCachingProxy Implemented using normal HTTP commands it is useful only in the context of HTTP requests FtpCachingProxy Implemented using an FTP proxy it is useful only in the context of FTP requests Excluding some URLs can be added to the textbox below the proxy settings see fig 4 by pressing the button After that double click into the just created URL field and enter the URL you would like to exclude from using the proxy Obviously the button removes the selected entry If you need more detailed information about the different proxy settings please refer to the manual of the unterlaying QT library documentation at http doc trolltech com 4 5 qnetworkproxy htm1 ProxyType enum Figure 4 Proxy settings in QGIS amp QGIS Options lt keto gt General Rendering Host localhost f Port 64609 User Password Proxy type HttpCachingProxy se Exclude URLs Add You can modify the options according to your needs Some of the changes may require a restart of QGIS before they will be effective a A settings are saved in a texfile HOME config QuantumGIS qgis conf QGIS 1 1 0 User Guide 26 4 8 Spatial Bookmarks Tip 7 USING PROXIES Using proxies can sometimes be tricky It is useful to trial and error the above proxy types and check if they succeed in your ca
54. FEATURE DELETION SUPPORT When editing ESRI shapefiles the deletion of features only works if QGIS is linked to a GDAL version 1 3 2 or greater The OS X and Windows versions of QGIS available from the download site are built using GDAL 1 3 2 or higher QGIS 1 1 0 User Guide 57 5 WORKING WITH VECTOR DATA Snap Mode QGIS allows digitized vertices to be snapped to other vertices of the same layer To set the snapping tolerance go to Settings gt Options gt Digitizing On Mac go to QGIS gt Preferences on Linux gt Note that the snapping tolerance is in map units or pixels Saving Edited Layers When a layer is in editing mode any changes remain in the memory of QGIS Therefore they are not committed saved immediately to the data source or disk When you turn editing mode off or quit QGIS for that matter you are then asked if you want to save your changes or discard them If the changes cannot be saved e g disk full or the attributes have values that are out of range the QGIS in memory state is preserved This allows you to adjust your edits and try again 5 5 4 Creating a New Layer To create a new layer for editing choose New Vector Layer from the menu The New Vector Layer dialog will be displayed as shown in Figure 15 Choose the type of layer point line or polygon Note that QGIS does not yet support creation of 2 5D features i e features with X Y Z
55. NS 12 11 OGR Converter Plugin The OGR Layer Converter plugin adds the ability to convert vector data from one OGR supported vector format to another The plugin is very simple to run and only requires a few parameters to be specified before running e Source Format Datset Layer Enter OGR format and path to the vector file to be converted e Target Format Datset Layer Enter OGR format and path to the vector output file Figure 59 OGR Layer Converter Plugin amp OGR Layer Converter x Source Format ESRI Shapefile gt File Directory Dataset vmap0_shapefiles alaska shp Browse Layer alaska o Target Format GML A Dataset sample_data gml alaska gmi Browse cance 4 ok Using the Plugin 1 Start QGIS load the OGR converter plugin in the Plugin Manager see Section 11 1 1 and click on the OGR Layer Converter icon which appears in the QGIS toolbar menu The OGR Layer Converter plugin dialog appears as shown in Figure 2 Select the OGR supported format e g ESRI Shapefile Y and the path to the vector input file e g alaska shp in the Source area 8Supported formats may vary according to the installed GDAL OGR package QGIS 1 1 0 User Guide 140 12 11 OGR Converter Plugin 3 Select the OGR supported format e g filename e g alaska gm1 in the Target area 4 Click Ok
56. ON using a file manager on your computer Then click 5 We can use this wizard to create a new MAPSET within an existing LOCATION see Section 9 3 2 or to create a new LOCATION altogether Click on the radio button Create new location see Figure 26 6 Enter a name for the LOCATION we used alaska and click 7 Define the projection by clicking on the radio button Projection to enable the projection list 8 We are using Albers Equal Area Alaska feet projection Since we happen to know that it is represented by the EPSG ID 2964 we enter it in the search box Note If you want to repeat this process for another LOCATION and projection and haven t memorized the EPSG ID click on the projector icon in the lower right hand corner of the status bar see Section 8 3 work with GRASS this functionality will not be described here QGIS 1 1 0 User Guide 88 9 3 GRASS LOCATION and MAPSET 10 To define the default region we have to enter the LOCATION bounds in north south east and 12 13 14 15 16 Click Find to select the projection Click Next west direction Here we simply click on the button Set current QGIS extent to apply the extend of the loaded layer alaska shp as the GRASS default region extend Click We also need to define a MAPSET within our new LOCATION You can name it whatever you like we used demo Check out the summary to make sure it s corre
57. Password used with Username to connect to the database SSL mode How the SSL connection will be negotiated with the server These are the options e disable only try an unencrypted SSL connection e allow try a non SSL connection if that fails try an SSL connection e prefer the default try an SSL connection if that fails try a non SSL connection e require only try an SSL connection Note that massive speedups in PostGIS layer rendering can be achieved by disabling SSL in the connection editor QGIS 1 1 0 User Guide 33 5 WORKING WITH VECTOR DATA Optional you can activate follwing checkboxes e X Save Password e X Only look in the geometry_columns table e X Only look in the public schema Once all parameters and options are set you can test the connection by clicking on the Test Connect button Tip 9 QGIS USER SETTINGS AND SECURITY Your customized settings for QGIS are stored based on the operating system A the settings are stored in your home directory in qt qgisrc Ez the settings are stored in the registry Depending on your computing environment storing passwords in your QGIS settings may be a security risk 5 2 2 Loading a PostGIS Layer E Once you have one or more connections defined you can load layers from the PostgreSQL database Of course this requires having data in PostgreSQL See Section 5 2 4 for a discussi
58. Proxy settings in QGIS arden E E E N 26 5 Add Vector Layer Dialog Dy eee eed ab bs bd o a ena d 30 6 Open an OGR Supported Vector Layer Dialog ee ree 31 7 QGIS with Shapefile of Alaska loaded oona a 32 8 Vector Layer Properties Dialog s EEE E E ee ae 39 9 Symbolizing options Oe a eee he es oe bee 40 10 Select feature and choose action 0 0 00 0 ee eee 46 11 Vector properties dialog with diagram tab SEERE ee ee sd 48 12 Diagram from temperature data overlayed on a map ee eee eeraant 49 13 Edit snapping options on a layer basis Dead Lupo o e aa E 50 14 Enter Attribute Values Dialog after digitizing a new vector feature A 54 15 Creating a New Vector Dialog aw ios Gates be dad rip 59 16 Attribute Table for Alaska layer Donar ida rn EE ata 60 17 Query Builder at ache ee aes eee ws ee ee ee ee ee 61 18 Raster Layers Properties Dialog Ooae a eee a a lee or 64 19 Dialog for adding a WMS server showing its available layers re 71 20 Dialog for searching WMS servers after some keywords Mus oia ee ee 73 21 Adding a WFS layer BA 77 22 CRS tab in the QGIS Options Dialog O een a eke eee earn 80 23 Projection Dialog eo a ORAS Se Se ee be ok ee 82 24 Custom CRS Dialog O ee a E 83 25 GRASS data in the alaska LOCATION adapted from Neteler amp Mitasova 2008 2 87 26 Creating anew GRASS LOCATION or a new MAPSET in QGIS Do 88 27 GRASS Digitizing Toolbar o ee 92 28 GRASS Digitizing Category Tab o o o ooo o
59. RASS LOCATION browser In Figure 34 you can see the current working LOCATION with its MAPSETs In the left browser windows you can browse through all MAPSETs inside the current LOCATION The right browser window shows some meta information for selected raster or vector layers e g resolution bounding box data source connected attribute table for vector data and a command history The toolbar inside the tab offers following tools to manage the selected LOCATION e Oy Add selected map to canvas Copy selected map e Rename selected map QGIS 1 1 0 User Guide 98 9 9 The GRASS toolbox Figure 34 GRASS LOCATION browser amp 1 MERASSH OOS alaska demo Modules Tree Modules List Browser 40aQ9Uuo Vector airports Points 76 Lines 0 airports Boundaries 0 alaska Centroids 0 0 0 gtopo30 E rivers rivers200 Areas ES PERMANENT Islands North 1981991 58212934 South 436940 04186938 East 1406705 41471586 West 1365575 11220648 3D no History COMMAND vw in ogr 0 dsn C Downloads qgis_data vmapO airports sh p output airports min_area 0 0001 v Close e Y Delete selected map e Set current region to selected map O Refresh browser window The Rename selected map and Delete selected map only work with maps inside your cur rently selected MAPSET All other to
60. RE REPOSITORIES 2 2 4 5 0 eee eb dee ee deen dee eee ee bade 146 QGIS 1 1 0 User Guide xii 1 Foreword Welcome to the wonderful world of Geographical Information Systems GIS Quantum GIS QGIS is an Open Source Geographic Information System The project was born in May of 2002 and was established as a project on SourceForge in June of the same year We ve worked hard to make GIS software which is traditionally expensive proprietary software a viable prospect for anyone with basic access to a Personal Computer QGIS currently runs on most Unix platforms Windows and OS X QGIS is developed using the Qt toolkit http www trolltech com and C This means that QGIS feels snappy to use and has a pleasing easy to use graphical user interface GUI QGIS aims to be an easy to use GIS providing common functions and features The initial goal was to provide a GIS data viewer QGIS has reached the point in its evolution where it is being used by many for their daily GIS data viewing needs QGIS supports a number of raster and vector data formats with new format support easily added using the plugin architecture see Appendix A for a full list of currently supported data formats QGIS is released under the GNU General Public License GPL Developing QGIS under this license means that you can inspect and modify the source code and guarantees that you our happy user will always have access to a GIS program that is free of cost and ca
61. S B 3 GRASS Toolbox region and projection configuration modules This Section lists all graphical dialogs in the GRASS Toolbox to manage and change the current mapset region and to configure your projection Table 18 GRASS Toolbox Region and projection configuration modules Region and projection configuration modules in the GRASS Toolbox Module name Purpose g region save Save the current region as a named region g region zoom Shrink the current region until it meets non NULL data from a given raster map g region multiple raster Set the region to match multiple raster maps g region multiple vector Set the region to match multiple vector maps g proj print Print projection information of the current location g proj geo Print projection information from a georeferenced file raster vector or image g proj ascii new Print projection information from a georeferenced ASCII file containing a WKT projection description g proj proj Print projection information from a PROJ 4 projection description file g proj ascii new Print projection information from a georeferenced ASCII file containing a WKT projection description and create a new location based on it g proj geo new Print projection information from a georeferenced file raster vector or image and create a new location based on it g proj proj new Print projection information from a PROJ 4 projection
62. S data formats will support all three feature types so for many formats you will only be able to choose between one or two types 12 7 5 Downloading GPS data from a device QGIS can use GPSBabel to download data from a GPS device directly as new vector layers For this we use the Download from GPS tab of the GPS Tools dialog see Figure 53 Here we select the type of GPS device the port that it is connected to or usb if your GPS supports this the feature type that you want to download the GPX file where the data should be stored and the name of the new layer The device type you select in the GPS device menu determines how GPSBabel tries to communicate with your GPS device If none of the available types work with your GPS device you can create a new type see section 12 7 7 The port may be a file name or some other name that your operating system uses as a reference to the physical port in your computer that the GPS device is connected to It may also be simply usb QGIS 1 1 0 User Guide 128 12 7 GPS Plugin Figure 53 The download tool A Load GPX file Import other file Download from GPS Upload to GPS GPX Conversions This tool will help you download data from a GPS device Choose your GPS device the port it is connected to the feature type you want to download a name for your new layer and the GPX file where you want to store the data If your device isn t listed or if you want to change some settings you c
63. S examines your data QGIS 1 1 0 User Guide 68 7 Working with OGC Data QGIS supports WMS and WFS as data sources The support is native WFS is implemented as a plugin 7 1 What is OGC Data The Open Geospatial Consortium OGC is an international organization with more than 300 com mercial governmental nonprofit and research organisations worldwide lts members develop and implement standards for geospatial content and services GIS data processing and exchange Describing a basic data model for geographic features an increasing number of specifications are developed to serve specific needs for interoperable location and geospatial technology including GIS Further information can be found under http www opengeospatial org Important OGC specifications are e WMS Web Map Service e WFS Web Feature Service e WCS Web Coverage Service e CAT Web Catalog Service e SFS Simple Features for SQL e GML Geography Markup Language OGC services are increasingly being used to exchange geospatial data between different GIS imple mentations and data stores QGIS can now deal with three of the above specifications being SFS though support of the PostgreSQL PostGIS data provider see Section 5 2 WFS and WMS as a client 7 2 WMS Client 7 2 1 Overview of WMS Support QGIS currently can act as a WMS client that understands WMS 1 1 1 1 1 and 1 3 servers It has particularly been tested against publicly accessib
64. S includes a utility called shp2pgsql that can be used to import shapefiles into a PostGIS enabled database For example to import a shapefile named lakes shp into a PostgreSQL database named gis_data use the following command shp2pgsql s 2964 lakes shp lakes_new psql gis_data This creates a new layer named lakes_new in the gis_data database The new layer will have a spatial reference identifier SRID of 2964 See Section 8 for more information on spatial reference QGIS 1 1 0 User Guide 35 5 WORKING WITH VECTOR DATA systems and projections Tip 11 EXPORTING DATASETS FROM PosTGIS Like the import tool shp2pgsq1 there is also a tool to export PostGIS datasets as shapefiles pgsql2shp This is shipped within your PostGIS distribution SPIT Plugin QGIS comes with a plugin named SPIT Shapefile to PostGIS Import Tool SPIT can be used to load multiple shapefiles at one time and includes support for schemas To use SPIT open the Plugin Manager from the menu check the box next to the X SPIT plugin and click The SPIT icon will be added to the plugin toolbar To import a shapefile click on the SPIT tool in the toolbar to open the SPIT Shapefile to PostGIS Import Tool dialog Select the PostGIS database you want to con nect to and click on Now you can add one or more files to the queue by clicking on the Add button To process the files click on the button The progress of the import as well as any er
65. Tab QGIS provides the ability to perform an action based on the attributes of a feature This can be used to perform any number of actions for example running a program with arguments built from the attributes of a feature or passing parameters to a web reporting tool Actions are useful when you frequently want to run an external application or view a web page based on one or more values in your vector layer An example is performing a search based on an attribute value This concept is used in the following discussion Defining Actions Attribute actions are defined from the vector Layer Properties dialog To define an action open the vector Layer Properties dialog and click on the tab Provide a descriptive name for the action The action itself must contain the name of the application that will be executed when the action is invoked You can add one or more attribute field values as arguments to the application When the action is invoked any set of characters that start with a followed by the name of a field will be replaced by the value of that field The special characters will be replaced by the value of the field that was selected from the identify results or attribute table see Using Actions below Double quote marks can be used to group text into a single argument to the program script or command Double quotes will be ignored if preceded by a backslash If you have field names that are substrings of
66. This will add at least three WMS servers for you to use including the NASA JPL WMS server To define a new WMS server in the Server Connections section select Then enter the parameters to connect to your desired WMS server as listed in table 2 Table 2 WMS Connection Parameters Name A name for this connection This name will be used in the Server Connec tions drop down box so that you can distinguish it from other WMS Servers URL URL of the server providing the data This must be a resolvable host name the same format as you would use to open a telnet connection or ping a host Username Username to access a secured WMS server This parameter is optional Password Password for a basic authentificated WMS server This parameter is op tional If you need to set up a proxy server to be able to receive WMS services from the internet you can add your proxy server in the options Choose menu Settings gt gt Options and click on the tab There you can add your proxy settings and enable them by setting the Use proxy for web access Make sure that you select the correct proxy type from the Proxy type dropdown menu Once the new WMS Server connection has been created it will be preserved for future QGIS ses QGIS 1 1 0 User Guide 70 7 2 WMS Client sions Tip 25 ON WMS SERVER URLS Be sure when entering in the WMS server URL that you have the base URL
67. a QGIS supports vector data in a number of formats including those supported by the OGR library data provider plugin such as ESRI shapefiles MapInfo MIF interchange format and MapInfo TAB native format You find a list of OGR supported vector formats in Appendix A 1 QGIS also supports PostGIS layers in a PostgreSQL database using the PostgreSQL data provider plugin Support for additional data types eg delimited text is provided by additional data provider plugins This section describes how to work with several common formats ESRI shapefiles PostGIS layers and SpatialLite layers Many of the features available in QGIS work the same regardless of the vector data source This is by design and includes the identify select labeling and attributes functions Working with GRASS vector data is described in Section 9 5 1 ESRI Shapefiles The standard vector file format used in QGIS is the ESRI Shapefile Support is provided by the OGR Simple Feature Library http www gdal org ogr A shapefile actually consists of several files The following three are required e shp file containing the feature geometries e dbf file containing the attributes in dBase format e shx index file Shapefiles also can include a file with a prj suffix which contains the projection informa tion While it is very useful to have a projection file it is not mandatory A shapefile dataset can contain additional files For further details see th
68. ading a Shapefile 4isseeb eee es ee ie rete oe vy bead Xt 29 5 1 2 Improving Performance nanana aaa EGG 30 5 1 3 Loading a Mapinfo Layer lt o 022020 da A e Gare as 31 5 1 4 Loading an Arclnfo Binary Coverage 31 5 2 PostGIS LAU lt a a ad ee a A 32 5 2 1 Creating a stored Connection eee ee ee 33 5 2 2 Loading a PostGIS layer 26 cea ed ewe debe rar E Eee 34 5 2 3 Some details about PostgreSQL layers 34 5 2 4 Importing Data into PostgreSQL 35 5 25 Improving Performanc lt s a so cca ea a a a 37 5 3 SpatiaLite Layers A Oe poms ew Ee eR Be Re prec pees 38 5 4 The Vector Properties Dialog cee ei eee eee Re eee 38 SA1 Selec cae da AA EES EE a a a BEER EES 39 Se Se TaD es ee Se ee ee eR eR OS eee A 39 5 4 3 Meladata Tab 20 ee a ge Ke ee A E a gee eee oS 41 ETE Tab ee ok ed a ge ee ee ae ee ge eee 41 54 5 Aclons laD ceda ds oe eS SAA a a da 43 046 Sues TB 22 A da AA n 46 547 Diagram Tab 2 a e a a de 47 Oe EO A tee Se AA 49 5 5 1 Setting the Snapping Tolerance and Search Radius 50 5 5 2 Topological editing 2 os wen eR eked ee Oe oa eRe OER ESS SES 51 5 5 3 Editing an Existing Layer lt so c 6264420444 e e Sh4 458 Saree 51 5 5 4 Creating a New Layer chek ee he WER RESS eee he OES EEA 58 5 5 5 Working with the Attribute Table 0 58 56 Query Builder lt ssas saagad radore
69. ailable Zooming and panning with the mouse wheel While digitizing you can press the mouse wheel to pan inside of the main window and you can roll the mouse wheel to zoom in and out on the map For zooming place the mouse cursor inside the map area and roll it forward away from you to zoom in and backwards towards you to zoom out The mouse cursor position will be the center of the zoomed area of interest You can customize the behavior of the mouse wheel zoom using the Map tools tab under the Settings gt Options menu Panning with the arrow keys Panning the Map during digitizing is possible with the arrow keys Place the mouse cursor inside the map area and click on the right arrow key to pan east left arrow key to pan west up arrow key to pan north and down arrow key to pan south You can also use the spacebar to temporarily cause mouse movements to pan then map The PgUp and PgDown keys on your keyboard will cause the map display to zoom in or out without interrupting your digitising session You can perform the following editing functions e Add Features A Capture Point Bal Capture Line and Capture Polygon e O Add Ring Sy Add Island QGIS 1 1 0 User Guide 52 5 5 Editing Tip 15 SAVE REGULARLY Remember to toggle Toggle editing also confirms that your data source can accept all your changes off re
70. ake the lakes layer active 4 Open the Layer Properties dialog 5 Click on the tab 6 Check the X Display labels checkbox to enable labeling 7 Choose the field to label with We ll use Field containing label NAMES Y 8 Enter a default for lakes that have no name The default label will be used each time QGIS encounters a lake with no value in the NAMES field 9 If have labels extending over several lines check X Multiline labels QGIS will check for a true line return in your label field and insert the line breaks accordingly A true line return is a single character n not two separate characters like a backlash followed by the character n 10 Click Apply Now we have labels How do they look They are probably too big and poorly placed in relation to the marker symbol for the lakes Select the entry and use the and buttons to set the font and color You can also change the angle and the placement of the text label To change the position of the text relative to the feature 1 Click on the entry 2 Change the placement by selecting one of the radio buttons in the Placement group To fix our labels choose the Right radio button 3 the Font size units allows you to select between Points or Map units 4 Click Apply to see your changes without closing the dialog Things are looking better but the labels are still too
71. all loc Import all the OGR PostGIS vector layers in a given data source and create a fitted location Table 16 GRASS Toolbox Vector data export modules Vector data export modules in the GRASS Toolbox Module name Purpose v out ogr Export vector layer to various formats OGR library v out ogr gml Export vector layer to GML v out ogr postgis Export vector layer to various formats OGR library v out ogr mapinfo Mapinfo export of vector layer v out ascii Convert a GRASS binary vector map to a GRASS ASCII vector map v out dxf converts a GRASS vector map to DXF QGIS 1 1 0 User Guide 156 B 2 GRASS Toolbox data type conversion modules B 2 GRASS Toolbox data type conversion modules This Section lists all graphical dialogs in the GRASS Toolbox to convert raster to vector or vector to raster data in a currently selected GRASS location and mapset Table 17 GRASS Toolbox Data type conversion modules Data type conversion modules in the GRASS Toolbox Module name Purpose r to vect point Convert a raster to vector points r to vect line Convert a raster to vector lines r to vect area Convert a raster to vector areas v to rast constant Convert a vector to raster using constant v to rast attr Convert a vector to raster using attribute values QGIS 1 1 0 User Guide 157 B GRASS TOOLBOX MODULE
72. alues or a range of values that are allowed to be added to the specific attribute table columns They are used to produce different edit widgets in the attribute dialog These widgets are e line edit an edit field which allows to enter simple text or restrict to numbers for numeric attributes e unique value a list of unique attribute values of all pre existing features is produced and pre sented in a combo box for selection e unique value editable a combination of line edit and unique value The edit field completes entered values to the unique value but also allows to enter new values e value map a combobox to select from a set of values specified in the value column the tab The possible values are delimited by a semicolon e g high medium Low It is also possible to prepend a label to each value which is delimited with an equal sign e g high 1 medium 2 low 3 The label is shown in the combobox instead of the value e classification if a unique value renderer is selected for the layer the values used for the classes are presented for selection in a combobox e range editable A edit field that allows to restrict numeric values to a given range That range is specified by entering minium and maximum value delimited by a semicolon e g 0 360 in the value column of the Attributes tab e range slider A slider widget is presented that allows selection of a value in a given range and precision The
73. alysis with the GRASS Toolbox see Section 9 9 9 2 Loading GRASS raster and vector layers With the GRASS plugin you can load vector or raster layers using the appropriate button on the toolbar menu As an example we use the QGIS alaska dataset see Section 3 2 It includes a small sample GRASS LOCATION with 3 vector layers and 1 raster elevation map 1 Create a new folder grassdata download the QGIS alaska dataset qgis_sample_data zip from http download osgeo org qgis data and unzip the file into grassdata 2 Start QGIS 3 If not already done in a previous QGIS session load the GRASS plugin clicking on gt Manage Plugins and selecting GRASS The GRASS toolbar appears on the toolbar menu In the GRASS toolbar click the av Open mapset icon to bring up the MAPSET wizard For Gisdbase browse and select or enter the path to the newly created folder grassdata You should now be able to select the LOCATION alaska and the MAPSET demo Click Notice that some previously disabled tools in the GRASS toolbar are now enabled N O Oo A 8 Click on A Add GRASS raster layer choose the map name gtopo30 and click The elevation layer will be visualized 9 Click on Py Add GRASS vector layer choose the map name alaska and click The alaska boundary vector layer will be overlayed on top of the gtopo30 map You can now adapt the layer properties as described in chapter 5 4 e g change
74. an also edit the devices This tool uses the program GPSBabel http www gpsbabel orq to transfer the data This requires that you have GPSBabel installed where QGIS can find it GPS device Garmin serial Edit devices Port usb c Refresh Feature type Waypoints gt Output file qgis_sample_data gps downloaded gpx Save As Layer name downloaded_points Help cancel 45 ok for usb enabled GPS units amp On Linux this is something like dev ttyS0 or dev ttyS1 and on gy Windows it s COM1 or COM2 When you click the data will be downloaded from the device and appear as a layer in QGIS 12 7 6 Uploading GPS data to a device You can also upload data directly from a vector layer in QGIS to a GPS device using the Upload to GPS tab of the GPS Tools dialog To do this you simply select the layer that you want to upload which must be a GPX layer your GPS device type and the port or usb that it is connected to Just as with the download tool you can specify new device types if your device isn t in the list This tool is very useful in combination with the vector editing capabilities of QGIS It allows you to load a map create waypoints and routes and then upload them and use them on your GPS device 12 7 7 Defining new device types There are lots of different types of GPS devices The QGIS developers can t test all of them so
75. anagement modules in the GRASS Toolbox Module name Purpose r random Creates a random vector point map contained in a raster r random cells Generates random cell values with spatial dependence v kernel Gaussian kernel density r contour Produces a contours vector map with specified step from a raster map r contour2 Produces a contours vector map of specified contours from a raster map r surf fractal Creates a fractal surface of a given fractal dimension r surf gauss GRASS module to produce a raster map layer of gaussian deviates whose mean and standard deviation can be expressed by the user r surf random Produces a raster map layer of uniform random deviates whose range can be expressed by the user r bilinear Bilinear interpolation utility for raster map layers v surf bispline Bicubic or bilinear spline interpolation with Tykhonov regularization r surf idw Surface interpolation utility for raster map layers r surf idw2 Surface generation program r surf contour Surface generation program from rasterized contours v surf idw Interpolate attribute values IDW v surf rst Interpolate attribute values RST r fillnulls Fills no data areas in raster maps using v surf rst splines interpolation Table 23 GRASS Toolbox Change raster category values and labels modules Raster category and label modules in the GRASS Toolbox Module name Purpose r recla
76. and PDF exported to image formats or to SVG 7 and you can save the layout as template and load it again in another session See a list of tools in table 4 Table 4 Print Composer Tools o O 5 Purpose Purpose Load from template Save as template ar Le Export to an image format Export print composition to SVG Print or export as PDF or Postscript Zoom to full extend Zoom in Zoom out Refresh view Add new map from QGIS map canvas Add Image to print composition Add label to print composition Add new legend to print composition Add new scalebar to print composition Select Move item in print composition Move content within an item Group items of print composition Ungroup items of print composition Raise selected items Lower selected items fe Siti OL Move selected items to top Move selected items to bottom El Align selected items left Align selected items right 25 1 Align selected items center Align selected items center vertical E T Align selected items top EEE EEEE Align selected items bottom LA To access the print composer click on the i Print Composer Print button in the toolbar or choose gt Export to SVG supported but it is not working properly with some recent QT4 versions You should try and check individual on your system QGIS 1 1 0 User
77. and activate the Enable on the fly projection checkbox The projector icon will show a green hook and all subsequently loaded vector layers will be OTF projected to the defined CRS The Coordinate Reference System tab of the Project Properties dialog contains four important components as shown in Figure 23 and described below 1 Enable on the fly projection this checkbox is used to enable or disable OTF projection When off each layer is drawn using the coordinates as read from the data source When on the coordinates in each layer are projected to the coordinate reference system defined for the map canvas 2 Coordinate Reference System this is a list of all CRS supported by QGIS including Geo graphic Projected and Custom coordinate reference systems To use a CRS select it from the list by expanding the appropriate node and selecting the CRS The active CRS is preselected 3 Proj4 text this is the CRS string used by the Proj4 projection engine This text is read only and provided for informational purposes 4 Search if you know the EPSG identifier or the name for a Coordinate Reference System you can use the search feature to find it Enter the identifier and click on 5 Recently used CRS if you have certain CRS that you frequently use in your everyday GIS work these will be displayed as quick access buttons at the bottom of the Projection Dialog Cl
78. ap to a round number when the canvas is resized Automatically snap to round number on resize 8 Click OK Figure 46 Scale Bar Plugin Scale Bar Plugin x Scale Bar Plugin This plugin draws a scale bar on the map Please note the a size option below is a preferred size and may have tobe altered by QGIS depending on the level of zoom The size is measured according to the map units specified in the project iba Placement Top Left s Scale bar style Tick Down Colour of bar e ell Size of bar 30 degrees E bd v Enable scale bar y Automatically snap to round number on resize B Help l 9 Cancel QGIS 1 1 0 User Guide 120 12 4 Dxf2Shp Converter Plugin 12 4 Dxf2Shp Converter Plugin The dxf2shape converter plugin can be used to convert vector data from DXF to Shapefile format lt requires the following parameters to be specified before running e Input DXF file Enter path to the DXF file to be converted Output Shp file Enter desired name of the Shapefile to be created Output file type Specify the geometry type of the output Shapefile Currently supported types are polyline polygone and point Export text labels When this checkbox is enabled an additional Shapefile point layer will be created and the associated dbf table will contain information about the TEXT fields found in the dxf file and the text strings themselves Figu
79. ar Calculates univariate statistics on selected table column for a GRASS vector map QGIS 1 1 0 User Guide 167 B GRASS TOOLBOX MODULES B 8 GRASS Toolbox 3D modules This Section lists all graphical dialogs in the GRASS Toolbox to work with 3D data GRASS provides more modules but they are currently only available using the GRASS Shell Table 35 GRASS Toolbox 3D Visualization 3D visualization and analysis modules in the GRASS Toolbox Module name Purpose nviz Open 3D View in nviz B 9 GRASS Toolbox help modules The GRASS GIS Reference Manual offers a complete overview of the available GRASS modules not limited to the modules and their often reduced functionalities implemented in the GRASS Toolbox Table 36 GRASS Toolbox Reference Manual Reference Manual modules in the GRASS Toolbox Module name Purpose g manual Display the HTML manual pages of GRASS QGIS 1 1 0 User Guide 168 C GNU General Public License GNU GENERAL PUBLIC LICENSE Version 2 June 1991 Copyright C 1989 1991 Free Software Foundation Inc 59 Temple Place Suite 330 Boston MA 02111 1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document but changing it is not allowed Preamble The licenses for most software are designed to take away your freedom to share and change it By contrast the GNU General Public License
80. art QGIS select Project Properties from the KDE Windows or File Gnome OSX menu and click on the tab As an alternative you you can also click on the projector icon in the lower right hand corner of the statusbar 2 Click on the X Enable on the fly projection tem of your choice see also Section 8 checkbox and select a projected coordinate sys 3 Load the coordinate capture plugin in the Plugin Manager see Section 11 1 1 and ensure that the dialog is visible by going to View gt Panels and ensuring that Coordinate Capture is enabled The cordinate capture dialog appears as shown in Figure 43 4 Click on the Click to the select the CRS to use for coordinate display different CRS from the one you selected above 5 To start capturing coordinates click on Start capture You can now click anywhere on the map canvas and the plugin will show the coordinates for both of your selected CRS Qe 6 To enable mouse coordinate tracking click the mouse tracking icon 7 You can also copy selected coordinates to the clipboard icon and select a QGIS 1 1 0 User Guide 117 12 USING QGIS CORE PLUGINS 12 3 Decorations Plugins The Decorations Plugins includes the Copyright Label Plugin the North Arrow Plugin and the Scale Bar Plugin They are used to decorate the map by adding cartographic elements 12 3 1 Copyrigh
81. ary array r out png Export GRASS raster as non georeferenced PNG image format r out ppm Converts a GRASS raster map to a PPM image file at the pixel resolu tion of the CURRENTLY DEFINED REGION r out ppm3 Converts 3 GRASS raster layers R G B to a PPM image file at the pixel resolution of the CURRENTLY DEFINED REGION r out pov Converts a raster map layer into a height field file for POVRAY r out tiff Exports a GRASS raster map to a 8 24bit TIFF image file at the pixel resolution of the currently defined region r out vrml Export a raster map to the Virtual Reality Modeling Language VRML QGIS 1 1 0 User Guide 155 B GRASS TOOLBOX MODULES Table 15 GRASS Toolbox Vector data import modules Vector data import modules in the GRASS Toolbox Module name Purpose v in dxf Import DXF vector layer v in e00 Import ESRI E00 file in a vector map v in garmin Import vector from gps using gpstrans v in gpsbabel Import vector from gps using gpsbabel v in mapgen Import MapGen or MatLab vectors in GRASS v in ogr Import OGR PostGIS vector layers v in ogr qgis Import loaded vector layers into GRASS binary vector map v in ogr loc Import OGR PostGIS vector layers and create a fitted location v in ogr qgis loc Import loaded vector layers into GRASS binary vector map and create a fitted location v in ogr all Import all the OGR PostGIS vector layers in a given data source v in ogr
82. as a point shapefile Useful for locating road or stream intersections ignores line intersections with length gt 0 QGIS 1 1 0 User Guide 131 12 USING QGIS CORE PLUGINS Table 7 fTools Research tools Research tools available via the fTools plugin Tool Purpose a EHE gt Random selection Randomly select n number of features or n percentage of features E Random selection within subsets Randomly select features within subsets based on a unique ID field Random points Generate pseudo random points over a given input layer Regular points Generate a regular grid of points over a specified region and export them as a point shapefile Vector grid Generate a line or polygon grid based on user specified grid spacing Select by location Select features based on their location relative to another layer to form a new selection or add or subtract from the current selection E Se A Polygon from layer Create a single rectangular polygon layer from the extent of an input extent raster or vector layer Table 8 fTools Geoprocessing tools Geoprocessing tools available via the fTools plugin Icon Tool Purpose Ca Convex Create minimum convex hull s for an input layer or based on an ID field hull s Buffer s Create buffer s around features based on distance or distance field E Intersect Overlay layers suc
83. as closed polygons but by one or more boundaries A boundary between two adjacent areas is digitized only once and it is shared by both areas Boundaries must be connected without gaps An area is identified labeled by the centroid of the area Besides boundaries and centroids a vector map can also contain points and lines All these geometry elements can be mixed in one vector and will be represented in different so called layers inside one GRASS vector map So in GRASS a layer is not a vector or raster map but a level inside a vector layer This is important to distinguish carefully It is possible to store more layers in one vector dataset For example fields forests and lakes can be stored in one vector Adjacent forest and lake can share the same boundary but they have separate attribute tables It is also possible to attach attributes to boundaries For example the boundary between lake and forest is a road so it can have a different attribute table The layer of the feature is defined by layer inside GRASS Layer is the number which defines if there are more than one layer inside the dataset e g if the geometry is forest or lake For now it can be only a number in the future GRASS will also support names as fields in the user interface Attributes can be stored inside the GRASS LOCATION as DBase or SQLITES3 or in external database tables for example PostgreSQL MySQL Oracle etc Attributes in
84. ase if one is not already defined e Connect to the database QGIS 1 1 0 User Guide 32 5 2 PostGIS Layers e Select the layer to add to the map e Optionally provide a SQL where clause to define which features to load from the layer e Load the layer 5 2 1 Creating a stored Connection amp The first time you use a PostGIS data source you must create a connection to the PostgreSQL database that contains the data Begin by clicking on the e Add a PostGIS Layer toolbar button selecting the Add a PostGIS Layer option from the menu or typing D You can also open the open the Add Vector Layer dialog and select Database The Add PostGIS Table s dialog will be displayed To access the connection manager click on the button to display the Create a New PostGIS Connection dialog The parameters required for a connection are shown in table 1 Table 1 PostGIS Connection Parameters Name A name for this connection Can be the same as Database Host Name of the database host This must be a resolvable host name the same as would be used to open a telnet connection or ping the host If the database is on the same computer as QGIS simply enter localhost here Database Name of the database Port Port number the PostgreSQL database server listens on The default port is 5432 Username User name used to login to the database Password
85. aska 2 778535 6 7 Alaska 0 359589 7 8 Alaska 0 225724 8 9 Alaska 0 136504 9 10 Alaska 1 272344 10 11 Alaska 0 095759 E ESQ look tor in cat 2 Show selected records only Advanced search 5 6 Query Builder The Query Builder allows you to define a subset of a table and display it as a layer in QGIS It can currently only be used with PostGIS layers For example if you have a towns layer with a population field you could select only larger towns by entering population gt 100000 in the SQL box of the query builder Figure 17 shows an example of the query builder populated with data from a PostGIS layer with attributes stored in PostgreSQL The query builder lists the layer s database fields in the list box on the left You can get a sample of the data contained in the highlighted field by clicking on the Sample button This retrieves the first 25 distinct values for the field from the database To get a list of all possible values for a field click on the button To add a selected field or value to the query double click on it You can use the various buttons to construct the query or you can just type it into the SQL box To test a query click on the button This will return a count of the number of records that will be included in the layer When satisfied with the query click OK The SQL for the where clause will be shown in the SQL column of the layer list Tip 22 CHANGING THE LAYER DEFINITION You can change the layer d
86. asova 2008 2 GRASS Database LOCATION MAPSET Geometry and attribute data home user grassdata all Vector layers 9 3 1 Creating a new GRASS LOCATION As an an example you find the instructions how the sample GRASS LOCATION alaska which is projected in Albers Equal Area projection with unit feet was created for the QGIS sample dataset This sample GRASS LOCATION alaska will be used for all examples and exercises in the following GRASS GIS related chapters It is useful to download and install the dataset on your computer 3 2 This is not strictly true with the GRASS modules r external and v external you can create read only links to external GDAL OGR supported data sets without importing them But because this is not the usual way for beginners to QGIS 1 1 0 User Guide 87 9 GRASS GIS INTEGRATION Figure 26 Creating a new GRASS LOCATION or a new MAPSET in QGIS amp NEW Vapset GRASS Location Location Select location spearfish60 X The GRASS location is a collection of maps for a particular territory or project lt Back m gt Cancel 1 Start QGIS and make sure the GRASS plugin is loaded 2 Visualize the alaska shp Shapefile see Section 5 1 1 from the QGIS alaska dataset 3 2 3 In the GRASS toolbar click on the atv Open mapset con to bring up the MAPSET wizard 4 Select an existing GRASS database GISDBASE folder grassdata or create one for the new LOCATI
87. at category value shall be applied to new geometry elements Next not used apply next not yet used category value to geometry element QGIS 1 1 0 User Guide 92 9 7 Digitizing and editing a GRASS vector layer Table 3 GRASS Digitizing Tools Icon Tool Purpose e New Point Digitize new point p New Line Digitize new line finish by selecting new tool New Boundary Digitize new boundary finish by selecting new tool New Centroid Digitize new centroid label existing area Move vertex Move one vertex of existing line or boundary and identify new position Add vertex Add a new vertex to existing line Delete vertex Delete vertex from existing line confirm selected vertex by another click 1 AO Move element Move selected boundary line point or centroid and click on new position Split line Split an existing line to 2 parts Delete element Delete existing boundary line point or centroid confirm selected element by another click li a Edit attributes Edit attributes of selected element note that one element can represent more features see above Close Close session and save current status rebuilds topology afterwards Manual entry manually define the category value for the geometry element in the Category entry field No category Do not apply a category value to the geometry element Thi
88. ath To be sure we could rewrite the first example as opt kde3 bin konqueror http www google com search q nam This will ensure that the konqueror application will be executed when the action is invoked The second example uses the notation which does not rely on a particular field for its value When the action is invoked the will be replaced by the value of the selected field in the identify results or attribute table Using Actions Actions can be invoked from either the Identify Results dialog or an Attribute Table dialog Recall that these dialogs can be opened by clicking Identify Features Or Open Table To invoke an action right click on the record and choose the action from the popup menu Actions are listed in the popup menu by the name you assigned when defining the actions Click on the action you wish to invoke If you are invoking an action that uses the notation right click on the field value in the Identify Results dialog or the Attribute Table dialog that you wish to pass to the application or script Here is another example that pulls data out of a vector layer and inserts them into a file using bash and the echo command so it will only work a or perhaps X The layer in question has fields for a species name taxon_nane latitude lat and longitude long would like to be able to make a spatial selection of a localities and export
89. ation 168 GRASS Toolbox Reference Manual 168 QGIS 1 1 0 User Guide x QGIS Tips QGIS Tips 1 UP TO DATE DOCUMENTATION s or a ru fryen do a a 1 2 EXAMPLE USING COMMAND LINE ARGUMENTS wena 13 3 RESTORING TOOLBARS o he eb eee ee ee ee ae 17 4 ZOOMING THE MAP WITH THE MOUSE WHEEL 0 0000 ee ae 19 5 PANNING THE MAP WITH THE ARROW KEYS AND SPACE BAR 19 6 CALCULATING THE CORRECT SCALE OF YOUR MAP CANVAS 00 20 7 USING PROXIES ae a a a e a a aa a w E a a e E E a a a 27 8 LAYER COLORS 20 a SS a ea A de a a Ge a A 30 9 QGIS USER SETTINGS AND SECURITY 34 10 POSTGIS LAYERS cocoa donada da a id ds dee dees 35 11 EXPORTING DATASETS FROM POSTGIS 36 12 IMPORTING SHAPEFILES CONTAINING POSTGRESQL RESERVED WORDS 36 13 DATAMINTEGRIT Y lt 2 24 4 eu be ek eee ee be Oe ed eS ee ee eh ad 52 14 MANIPULATING ATTRIBUTE DATA nwa nnana ne aa 52 15 GAVE REGULARLY joc Boh DE GEES SE Ae he he REE PAG CS he ee 53 16 CONCURRENT EDITS lt 4 2 640084844004 ea wh ed Bod we or ewe 53 17 ZOOM IN BEFORE EDITING 0 a a a 54 18 VERTEX MARKERS cc 0 ened i e Ga a ak a ww es te 54 19 ATTRIBUTE VALUE TYPES 2 coac rasanne eae ee aa 55 20 CONGRUENCY OF PASTED FEATURES 5 62 0200 800 cee arai 57 21 FEATURE DELETION SUPPORT 2 20 4 2 4 600 2 4 4024
90. ation about tools and toolbars see Section 4 2 2 Menu Option New Project 2 Open Project i Save Project Save Project As mI Save as Image a Print Composer O Exit 4 Cut Features 2 Copy Features 23 Paste Features Capture Point ts Capture Line rt Capture Polygon Open Recent Projects Shortcut Ctrl N Ctrl O Ctrl S Ctrl Shift S Ctrl P Cirl Q Be C Ctrl Ctr d EE Ctrl And Other Edit Menu Items amp Zoom In Select Features Identify Features im Measure Line amp Measure Area El Zoom Full Ctrl Ctrl eee ag Reference see Section 4 5 see Section 4 5 see Section 4 5 see Section 4 5 see Section 4 5 see Section 4 6 see Section 10 see Section 5 5 3 see Section 5 5 3 see Section 5 5 3 see Section 5 5 3 see Section 5 5 3 see Section 5 5 3 see Section 5 5 3 Toolbar Xx Xx Xx Xx B BE EE File File File Digitizing Digitizing Digitizing Digitizing Digitizing i X Digitizing Digitizing Xx Map Navigation Xx Map Navigation Xx Map Navigation Xx Attributes Xx Attributes Xx Attributes X Attributes Map Navigation QGIS 1 1 0 User Guide 15 4 FEATURES AT A GLANCE amp Zoom To Layer Q Zoom To Selection Zoom Last 4 Zoom Next Zoom Actual Size 2 Map Tips New Bookmark A Show Bookmarks
91. ayers appear It is now possible to drag a file from one file group into another one If this is done the symbologies are grouped Note that QGIS only permits the drag if the two layers are able to share symbology same vector geometry type and same attributes 4 2 4 Map View This is the business end of QGIS maps are displayed in this area The map displayed in this window will depend on the vector and raster layers you have chosen to load see sections that follow for more information on how to load layers The map view can be panned shifting the focus of the map display to another region and zoomed in and out Various other operations can be performed on the map as described in the toolbar description above The map view and the legend are tightly bound to each other the maps in view reflect changes you make in the legend area Tip 4 ZOOMING THE MAP WITH THE MOUSE WHEEL You can use the mouse wheel to zoom in and out on the map Place the mouse cursor inside the map area and roll the wheel forward away from you to zoom in and backwards towards you to zoom out The mouse cursor position is the center where the zoom occurs You can customize the behavior of the mouse wheel zoom using the Map tools tab under the Settings gt Options menu Tip 5 PANNING THE MAP WITH THE ARROW KEYS AND SPACE BAR You can use the arrow keys to pan in the map Place the mouse cursor inside the map area and click on the righ
92. bdataset list will now show the Raster Data Table and Raster ld s pairs At anytime the Selection entry can be edited in order to go directly to a known GeoRaster or to go back to the beginning and select another table name The Selection data entry can also be used to enter a Where clause at the end of the identification string e g geor scott tiger orcl gdal_import raster geoid See http ww gdal org frmt_georaster html for more information 12 12 3 Displaying GeoRaster Finally by selecting a GeoRaster from the list of Raster Data Table and Raster Id s the raster image will be loaded into QGIS The Select Oracle Spatial GeoRaster dialog window can be closed now and next time it opens it will keep the same connection and will show the same previous list of subdataset making it very easy to open up another image from the same context Note GeoRasters that contains pyramids will display much faster but the pyramids need to be gen erated outside of QGIS using Oracle PL SQL or gdaladdo The following is example using gdaladdo gdaladdo georaster scott tiger orcl georaster _table georaster georid 6 r nearest 2 4 6 8 16 32 QGIS 1 1 0 User Guide 143 12 USING QGIS CORE PLUGINS Figure 61 Select Oracle GeoRaster dialog A Select Oracle Spatial GeoRaster Server Connections example Connect Delete Subdatasets georaster scotttigerorcl GDAL_RDT 214 georaster scotttigerorcl
93. by right clicking on the name in the legend and choosing from the popup menu See Section 5 4 2 for more information on setting symbology of vector layers 5 1 2 Improving Performance To improve the performance of drawing a shapefile you can create a spatial index A spatial index will improve the speed of both zooming and panning Spatial indexes used by QGIS have a qix extension Use these steps to create the index e Load a shapefile e Open the Layer Properties dialog by double clicking on the shapefile name in the legend or by right clicking and choosing from the popup menu QGIS 1 1 0 User Guide 30 5 1 ESRI Shapefiles Figure 6 Open an OGR Supported Vector Open an OGR Supported Vector Layer Layer Dialog A Look in 3 home stephan grassd _20 vmap0_shapefiles Hooo DJ BA Compu airports shp swamp shp A pla 3 alaska shp 3 trails shp Ls J builtups shp trees shp elevp shp tundra shp grassland shp lakes shp landice shp majrivers shp pipelines shp _ popp shp C railroads shp rivers shp storagep shp Open File name Files of type OGR ESRI Shapefiles shp SHP Encoding System Ls e In the tab General click the Create Spatial Index button 5 1 3 Loading a MapInfo Layer To load a MapInfo layer click on the Add a vector layer
94. ch gives you legal permission to copy distribute and or modify the software Also for each author s protection and ours we want to make certain that everyone understands that there is no warranty for this free software If the software is modified by someone else and passed on we want its recipients to know that what they have is not the original so that any problems introduced by others will not reflect on the original authors reputations Finally any free program is threatened constantly by software patents We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses in effect making the program proprietary To prevent this we have made it clear that any patent must be licensed for everyone s free use or not licensed at all The precise terms and conditions for copying distribution and modification follow TERMS AND CONDITIONS FOR COPYING DISTRIBUTION AND MODIFICATION QGIS 1 1 0 User Guide 169 C GNU GENERAL PUBLIC LICENSE 0 This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License The Program below refers to any such program or work and a work based on the Program means either the Program or any derivative work under copyright law that is to say a work containing the Program or a portion of it either verbatim or with modifications and or translate
95. ct and click The new LOCATION alaska and two MAPSETs demo and PERMANENT are created The currently opened working set is MAPSET demo as you defined Notice that some of the tools in the GRASS toolbar that were disabled are now enabled If that seemed like a lot of steps it s really not all that bad and a very quick way to create a LOCATION The LOCATION alaska is now ready for data import see Section 9 4 You can also use the already existing vector and raster data in the sample GRASS LOCATION alaska included in the QGIS alaska dataset 3 2 and move on to Section 9 5 9 3 2 Adding a new MAPSET A user has only write access to a GRASS MAPSET he created This means besides access to his own MAPSET each user can also read maps in other user s MAPSETs but he can modify or remove only the maps in his own MAPSET All MAPSETs include a WIND file that stores the current boundary coordinate values and the currently selected raster resolution Neteler amp Mitasova 2008 2 see Section 9 8 1 Start QGIS and make sure the GRASS plugin is loaded In the GRASS toolbar click on the New mapset icon to bring up the MAPSET wizard Select the GRASS database GISDBASE folder grassdata with the LOCATION alaska where we want to add a further MAPSET called test Click Next 5 We can use this wizard to create a new MAPSET within an existing LOCATION or to create a new LOCATION altogether Click on the radio button S
96. cumentation about the usage minimum QGIS version homepage authors and other important information are provided with the external plugins themselves and is not included in this manual 1 You will find an up to date list of Official plugins in the Official QGIS Repository at http qgis osgeo org download plugins html This list is also available automatically from the Plugins installer via E Fetch Python Plugins Table 12 Current moderated external QGIS Plugins Icon External plugin Description 1 HA Zoom To Point Zooms to a coordinate specified in the input dialog You can spec ify the zoom level as well to control the view extent E Plugin Installer The most recent Python Plugin Installer A detailed description of the installation procedure for external python plugins can be found in Section 11 1 2 Tip 45 ADD MORE REPOSITORIES To add the User contributed repository and or several external author repositories open the Plugin Installer Plugins gt E Fetch Python Plugins go to the tab and click Add 3rd party repositories If you do not want one or more of the added repositories they can be disabled via the button or completely removed with the button Updates of core plugins may be available in this repository as external overlays Tools Mapserver Export and the Plugin Installer are Python plugins but they are also part of the QGIS sources and a
97. d MAPSET 9 9 1 Working with GRASS modules The GRASS Shell inside the GRASS Toolbox provides access to almost all more than 300 GRASS modules in command line modus To offer a more user friendly working environment about 200 of the available GRASS modules and functionalities are also provided by graphical dialogs These dialogs are grouped in thematic blocks but are searchable as well You find a complete list of GRASS modules available in QGIS version 1 1 0 in appendix B It is also possible to customize the GRASS Toolbox content It is described in Section 9 9 3 As shown in Figure 32 you can look for the appropriate GRASS module using the thematically QGIS 1 1 0 User Guide 96 9 9 The GRASS toolbox Figure 32 GRASS Toolbox and searchable Modules List A GRASS Peel alaskaldemo GRASS g dlaska demo Modules Tree Modules List Browser Modules Tree Modules List Browser GRASS MODULES gt z r out gdal_gtiff BP shat GRASS shel V gt P gdal g n Export raster layer to Geo TIFF f File Import ea Epor y gt r out arc ql oe higo Converts a raster map layer into an ESRI ARCGAID file 7 r out gdal gtift Export raster layer to Geo TIFF 2 r out arc Converts a raster map layer into an Et X a y gt r out gridatb 2 r out gridatb Exports GRASS raster map to GRI g Exports GRASS raster map to GRIDATB FOR map file TOPMODEL 2 r out mat Exports a GRASS raster to a binary A y lt gt 1 ou
98. d into another language Hereinafter translation is included without limitation in the term modification Each licensee is addressed as you Activities other than copying distribution and modification are not covered by this License they are outside its scope The act of running the Program is not restricted and the output from the Program is covered only if its contents constitute a work based on the Program independent of having been made by running the Program Whether that is true depends on what the Program does 1 You may copy and distribute verbatim copies of the Program s source code as you receive it in any medium provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty keep intact all the notices that refer to this License and to the absence of any warranty and give any other recipients of the Program a copy of this License along with the Program You may charge a fee for the physical act of transferring a copy and you may at your option offer warranty protection in exchange for a fee 2 You may modify your copy or copies of the Program or any portion of it thus forming a work based on the Program and copy and distribute such modifications or work under the terms of Section 1 above provided that you also meet all of these conditions a You must cause the modified files to carry prominent notices stating that you changed the files and the date o
99. d so long as such parties remain in full compliance 5 You are not required to accept this License since you have not signed it However nothing else grants you permission to modify or distribute the Program or its derivative works These actions are prohibited by law if you do not accept this License Therefore by modifying or distributing the Program or any work based on the Program you indicate your acceptance of this License to do so and all its terms and conditions for copying distributing or modifying the Program or works based on it 6 Each time you redistribute the Program or any work based on the Program the recipient automatically receives a license from the original licensor to copy distribute or modify the Program subject to these terms and conditions You may not impose any further restrictions on the recipients exercise of the rights granted herein You are not responsible for enforcing compliance by third parties to this License 7 If as a consequence of a court judgment or allegation of patent infringement or for any other reason not limited to patent issues conditions are imposed on you whether by court order agreement or otherwise that contradict the conditions of this License they do not excuse you from the conditions of this License If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations then as a consequence you may not distribute the P
100. d their topological status e g closed opened boundary QGIS 1 1 0 User Guide 94 9 7 Digitizing and editing a GRASS vector layer Figure 30 GRASS Digitizing Symbolog Tab amp et ROn tAn Category Settings Symbology Table Line width i y Marker size e Y Type Line Boundary no area Boundary 1 area Boundary 2 areas Centroid in area Table Tab The tab provides information about the database table for a given layer Here you can add new columns to an existing attribute table or create a new database table for a new GRASS vector layer see Section 9 6 Figure 31 GRASS Digitizing Table Tab 4 Ss cots eo A E Category Settings Symbology Table Layer 1 int 11 string 30 Add Column Create Alter Table Tip 39 GRASS EDIT PERMISSIONS You must be the owner of the GRASS MAPSET you want to edit It is impossible to edit data layers in a MAPSET that is not yours even if you have write permissions QGIS 1 1 0 User Guide 95 9 GRASS GIS INTEGRATION 9 8 The GRASS region tool The region definition setting a spatial working window in GRASS is important for working with raster layers Vector analysis is per default not limited to any defined region definitions All newly created rasters will have the spatial extension and resolution of the currently defined GRASS region regardless of their original
101. dal appears Browse to the folder raster in the QGIS alaska dataset and select the file landcover img As raster output name define landcover_grass and click Run In the Output tab you see the currently running GRASS command r in gdal o input path to landcover img output landcover_grass When it says Succesfully finished click View output The landcover_grass raster layer is now imported into GRASS and will be visualized in the QGIS canvas To import the vector GML file lakes gm1 click the module v in ogr in the Modules Tree tab This GRASS module allows to import OGR supported vector files into a GRASS LOCATION The module dialog for v in ogr appears Browse to the folder gm1 in the QGIS alaska dataset and select the file lakes gm1 as OGR file As vector output name define lakes_grass and click Run You don t have to care about the other options in this example In the Output tab you see the currently running GRASS command v in ogr o dsn path to lakes gml output lakes_grass When it says Succesfully finished click View output The l1akes_grass vector layer is now imported into GRASS and will be visualized in the QGIS canvas QGIS 1 1 0 User Guide 90 9 5 The GRASS vector data model 9 5 The GRASS vector data model It is important to understand the GRASS vector data model prior to digitizing In general GRASS uses a topological vector model This means that areas are not represented
102. de 84 9 GRASS GIS Integration The GRASS plugin provides access to GRASS GIS 4 databases and functionalities This includes visualization of GRASS raster and vector layers digitizing vector layers editing vector attributes cre ating new vector layers and analysing GRASS 2D and 3D data with more than 300 GRASS modules In this Section we ll introduce the plugin functionalities and give some examples on managing and working with GRASS data Following main features are provided with the toolbar menu when you start the GRASS plugin as described in Section 9 1 Open mapset New mapset Close mapset Add GRASS vector layer Add GRASS raster layer Create new GRASS vector Edit GRASS vector layer Open GRASS tools Display current GRASS region E al Nal 2 9 E 4 Edit current GRASS region 9 1 Starting the GRASS plugin To use GRASS functionalities and or visualize GRASS vector and raster layers in QGIS you must select and load the GRASS plugin with the Plugin Manager Therefore click the menu gt Manage Plugins select and click QGIS 1 1 0 User Guide 85 9 GRASS GIS INTEGRATION You can now start loading raster and vector layers from an existing GRASS LOCATION see Section 9 2 Or you create a new GRASS LOCATION with QGIS see Section 9 3 1 and import some raster and vector data see Section 9 4 for further an
103. depending on your image accuracy requirements QGIS 1 1 0 User Guide 71 7 WORKING WITH OGC DATA Tip 26 IMAGE ENCODING You will typically find that a WMS server offers you the choice of JPEG or PNG image encoding JPEG is a lossy compression format whereas PNG faithfully reproduces the raw raster data Use JPEG if you expect the WMS data to be photographic in nature and or you don t mind some loss in picture quality This trade off typically reduces by 5 times the data transfer requirement compared to PNG Use PNG if you want precise representations of the original data and you don t mind the increased data transfer requirements Layers The section lists the layers available from the selected WMS server You may notice that some layers are expandible this means that the layer can be displayed in a choice of image styles You can select several layers at once but only one image style per layer When several layers are selected they will be combined at the WMS Server and transmitted to QGIS in one go Tip 27 WMS LAYER ORDERING In this version of QGIS WMS layers rendered by a server are overlaid in the order listed in the Layers section from top to bottom of the list If you want to overlay layers in the opposite order then you can select Add WMS layer a second time choose the same server again and select the second group of layers that you want to overlay the first group Transparency In this
104. depends on whether the loaded legend item you hold your mouse over is a raster or a vector layer For GRASS vector layers the toggle editing is not available See section 9 7 for information on editing GRASS vector layers e Right mouse button menu for raster layers Zoom to layer extent Zoom to best scale 100 Show in overview Remove Properties Rename Add Group Expand all Collapse all Show file groups an e Right mouse button menu for vector layers Zoom to layer extent Show in overview Remove Open attribute table Toggle editing not available for GRASS layers Save as shapefile Save selection as shapefile Properties Make to toplevel item Rename Add Group Expand all Collapse all pey Show file groups e Right mouse button menu for layer groups Remove Rename i QGIS 1 1 0 User Guide 18 4 2 QGIS GUI Show file groups If several vector data sources have the same vector type and the same attributes their symbolisations may be grouped This means that if the symbolisation of one data source is changed the others automatically have the new symbolisation as well To group symbologies open the right click menu in the legend window and choose Show file groups The file groups of the l
105. ding on the level of zoom You must have write access in the directory where the original data is stored to build pyramids Several resampling methods can be used to calculate the pyramides e Average e Nearest Neighbour QGIS 1 1 0 User Guide 67 6 WORKING WITH RASTER DATA When checking the checkbox Build pyramids internally if possible QGIS tries to build pyramids internally Please note that building pyramids may alter the original data file and once created they cannot be removed If you wish to preserve a non pyramided version of your raster make a backup copy prior to building pyramids 6 3 7 Histogram Tab The tab allows you to view the distribution of the bands or colors in your raster You must first generate the raster statistics by clicking the button You can choose which bands to display by selecting them in the list box at the bottom left of the tab Two different chart types are allowed e Bar chart e Line graph You can define the number of chart columns to use and decide whether you want to x Allow approximation or display X out of range values Once you view the histogram you ll notice that the band statistics have been populated on the tab Tip 24 GATHERING RASTER STATISTICS To gather statistics for a layer select pseudocolor rendering and click the Apply button Gathering statistics for a layer can be time consuming Please be patient while QGI
106. ds and data types If you want to make sure everything feature and its attributes gets copied make sure the schemas match Tip 20 CONGRUENCY OF PASTED FEATURES If your source and destination layers use the same projection then the pasted features will have geometry identical to the source layer However if the destination layer is a different projection then QGIS cannot guarantee the geometry is identical This is simply because there are small rounding off errors involved when converting between projections Deleting Selected Features If we want to delete an entire polygon we can do that by first selecting the polygon using the regular Select Features tool You can select multiple features for deletion Once you have the selec tion set use the Delete Selected tool to delete the features There is no undo function but remember your layer isn t really changed until you stop editing and choose to save your changes So if you make a mistake you can always cancel the save The Cut Features tool on the digitizing toolbar can also be used to delete features This effectively deletes the feature but also places it on a spatial clipboard So we cut the feature to delete We could then use the paste tool to put it back giving us a one level undo capability Cut copy and paste work on the currently selected features meaning we can operate on more than one atatime Tip 21
107. e Also scaling of colors are available Tip 23 VIEWING A SINGLE BAND OF A MULTIBAND RASTER If you want to view a single band for example Red of a multiband image you might think you would set the Green and Blue bands to Not Set But this is not the correct way To display the Red band set the image type to grayscale then select Red as the band to use for Gray 6 3 2 Transparency Tab QGIS has the ability to display each raster layer at varying transparency levels Use the transparency slider to indicate to what extent the underlying layers if any should be visible though the current raster layer This is very useful if you like to overlay more than one rasterlayer e g a shaded relief map overlayed by a classified rastermap This will make the look of the map more three dimensional Additionally you can enter a rastervalue which should be treated as NODATA QGIS 1 1 0 User Guide 65 6 WORKING WITH RASTER DATA An even more flexible way to customize the transparency can be done in the Custom transparency options section The transparency of every pixel can be set in this tab As an example we want to set the water of our example rasterfile landcover tif to a transparency of 20 The following steps are neccessary 1 Load the rasterfile landcover 2 Open the properties dialog by double clicking on the rasterfile name in the legend or by right clicking and choosing from the popup meun 3 select the T
108. e update all airports Color Frame Background E Background gtopo30 elevation map Opacity de Composer item properties Outline width 0 30 Color Frame Background Opacity Outline width 0 30 2 Position Frame Position Frame a legend item tab b scalebar item tab 10 1 4 Raise lower and align elements Raise or lower functionalities for elements are inside the Raise selected items pulldown menu Choose an element on the print composer canvas and select the matching functionality to raise or lower the selected element compared to the other elements see table 4 There are several alignment functionalities available within the iE Align selected items pulldown menu see table 4 To use an alignment functionality you first select some elements and then click on the matching alignment icon All selected will then be aligned within to their common bounding QGIS 1 1 0 User Guide 106 10 1 Using Print Composer box 10 1 5 Creating Output Figure 39 shows the print composer with an example print layout including each type of map element described in the sections above Figure 39 Print Composer with map view legend scalebar and text added QGIS print composer m1 SI XAQOR ag Segment Map units size map perbar unit units Segments o B segments Style Map Height m 5 Line width Label spa Box space Unit label Composer it
109. e 4 7 for location Locate the plugins settings and change all the plugin values to false to prevent them from loading amp For example to prevent the Delimited text plugin from loading the entry in HOME config QuantumGIS qgis conf on Linux should look like this Add Delimited Text Layer false Do this for each plugin in the Plugins section You can then start QGIS and add the plugins one at a time from the Plugin Manager to determine which plugin is causing the problem QGIS 1 1 0 User Guide 109 11 QGIS PLUGINS Figure 40 Plugin Manager QGIS Plugin Manager x To enable disable a plugin click its checkbox or description Add Delimited Text Layer a Loads and displays delimited text files containing x y coordinates Coordinate Capture Capture mouse coordinates in different CRS CopyrightLabel Draws copyright information Diagram Overlay A plugin for placing diagrams on vector layers y Dxf2Shp Converter Filter 4 Plugin Directory home cfarmer apps qgis libiqgis selectan Clear All cancel go 11 1 2 Loading an external QGIS Plugin There are two steps required to integrate external plugins into QGIS 1 Download an external plugin from a repository using the Plugin Installer Section 11 1 3 The new external plugin will be added to the list of available plugins in the Plugin Manager 2 Load the plugin using the Plugin Manager 11 1 3 Using the QGIS Python Plug
110. e ESRI technical specification at http www esri com library whitepapers pdfs shapefile pdf 5 1 1 Loading a Shapefile e To load a shapefile start QGIS and click on the e Add a vector layer toolbar button or simply type v This will bring up a new window see Figure5 From the available options check File Click on Browse That will bring up a standard open file dialog see Figure 6 which allows you to navigate the file system and load a shapefile or other supported data source The selection box Files of type Y allows you to preselect some OGR supported file formats QGIS 1 1 0 User Guide 29 5 WORKING WITH VECTOR DATA Figure 5 Add Vector Layer Dialog A a Add vector layer x Source type e File Directory Database Protocol Encoding System s Source Dataset Browse s Help cance You can also select the Encoding type for the shapefile if desired Selecting a shapefile from the list and clicking loads it into QGIS Figure 7 shows QGIS after loading the alaska shp file Tip 8 LAYER COLORS When you add a layer to the map it is assigned a random color When adding more than one layer at a time different colors are assigned to each layer Once loaded you can zoom around the shapefile using the map navigation tools To change the symbology of a layer open the Layer Properties dialog by double clicking on the layer name or
111. e conventions used in this manual are as follows GUI Conventions The GUI convention styles are intended to mimic the appearance of the GUI In general the objective is to use the non hover appearance so a user can visually scan the GUI to find something that looks like the instruction in the manual e Menu Options Layer gt RR Add a Raster Layer or gt gt e Tool Add a Raster Layer e Button Save as Default e Dialog Box Title Layer Properties e Toolbox Item E nviz Open 3D View in nviz e Checkbox XJ Render e Radio Button Postgis SRID e Select a Number O EPSG ID Hue 60 5 e Select a String Outline style Solid Line Y e Browse for a File e Select a Color Outline color e Slider Transparency 0 e Input Text Display Name A shadow indicates a clickable GUI component QGIS 1 1 0 User Guide 1 2 Conventions Text or Keyboard Conventions The manual also includes styles related to text keyboard commands and coding to indicate different entities such as classes or methods They don t correspond to any actual appearance e Hyperlinks http qgis org e Single Keystroke press P e Keystroke Combinations press Ctrl B meaning press and hold the Ctrl key and then press the B key e Name of a File lakes shp
112. e layer name box to specify the legend name for the new layer Use the delimiter box to specify what delimeter is used in your file e g space comma tab or a regular expression in Pert style After choosing a delimiter press the parse button and select the columns containing the x and y values for the layer Delimited text file ng qgis_sample_data csv elevp csv Browse Layer name elevp i Delimiter 9 Plain characters Regular expression lt X field x y Y field Y Sample text X Y ELEV 300120 7689960 13 654360 7562040 52 m L 1640 7512840 3 775720 7496440 49 756040 7489880 49 Il al Help Parse cancel 3 ok Once you have parsed the file choose the X and Y fields from the drop down lists and enter a Layer name e g elevp as shown in Figure 42 To add the layer to the map click Add Layer The delimited text file now behaves as any other map layer in QGIS QGIS 1 1 0 User Guide 116 12 2 Coordinate Capture Plugin 12 2 Coordinate Capture Plugin The coordinate capture plugin is easy to use and provides the ability to display coordinates on the map canvas for two selected Coordinate Reference Systems CRS Figure 43 Coordinate Cature Plugin amp Coordinate Capture DRE O 210508 603 136997 606 Jin 210508 603 136997 606 SS 7 Copy to clipboard Start capture 1 St
113. e the text boxes below to test the CRS definition you are creating Enter a coordinate where both the latong and the transformed result are known for example by reading off a map Then press the calculate button to see if the CRS definition you are creating is accurate Parameters Geographic WGS84 Destination CRS a Calculate and related command line utilities The cartographic parameters used with proj 4 are described in the user manual and are the same as those used by QGIS The Custom Coordinate Reference System Definition dialog requires only two parameters to define a user CRS 1 a descriptive name and 2 the cartographic parameters in PROJ 4 format QGIS 1 1 0 User Guide 83 8 WORKING WITH PROJECTIONS To create a new CRS click the 2 New button and enter a descriptive name and the CRS parameters After that you can save your CRS by clicking the button Save Note that the Parameters must begin with a proj block to represent the new coordinate reference system You can test your CRS parameters to see if they give sane results by clicking on the button inside the Test block and pasting your CRS parameters into the Parameters field Then en ter known WGS 84 latitude and longitude values in North and East fields respectively Click on and compare the results with the known values in your coordinate reference system QGIS 1 1 0 User Gui
114. eam does not recommend installing these plugins unless you intend to use them for testing purposes 11 2 Data Providers Data Providers are special plugins that provides access to a data store By default QGIS supports PostGIS layers and disk based data stores supported by the GDAL OGR library Appendix A 1 A Data Provider plugin extends the ability of QGIS to use other data sources Data Provider plugins are registered automatically by QGIS at startup They are not managed by the Plugin Manager but used behind the scenes when a data type is added as a layer in QGIS QGIS 1 1 0 User Guide 113 12 USING QGIS CORE PLUGINS 12 Using QGIS Core Plugins QGIS currently contains 19 core plugins that can be loaded using the Plugin Manager Table 5 lists each of the core plugins along with a description of their purpose and the toolbar icon Table 5 QGIS Core Plugins o O 5 Plugin Description Add Delimited Text Layer Loads and displays delimited text files containing x y coordinates Coordinate Capture Capture mouse coordinate in different CRS Copyright Label Draws a copyright label with information Diagram Overlay Place charts pie or bar or proportional symbols over vector layers DXF2Shape Converter Converts from DXF to SHP file format fTools A suite of analysis geometry geoprocessing and research tools GPS Tools Tools for loading and importing GPS data GRASS Act
115. ecified field Unique value objects are classified by the unique values within a specified field with each value having a different symbol To change the symbology for a layer simply double click on its legend entry and the vector Layer Properties dialog will be shown Figure 9 Symbolizing options A i Layer Properties ES Layer Propertie a ae General Symbology Metadata Labels Actions Attributes General Symbology Metadata Labels Actions Attributes Legend type Single symbol Fansparency 0 gm Graduated Symbol y transparency 0 cat ly Equal interval x e E ett Classfy Delete class Label Style Options Outline style solid Line a Style Options Dan si E Outline style Solid Line Outline width 0 40 El q_o Outline width 0 40 El Fil style sold BEJ Fil color SS Ail syle ua Restore Default style Save As Default ji Load Style Save Style Restore Default Style Save As Default j Load Style y Save Style Help oe Apply cancel Help apply cancel a Single symbol b Graduated symbol i Layer Properties 280z General Symbology Metadata Labels Actions Attributes General Symbology Metadata Labels Actions Attributes Legend type cCortinuaus coler 7 rarsparency 0 q Legend type unique Value Tansparency 0
116. efinition after it is loaded by altering the SQL query used to define the layer To do this open the vector Layer Properties dialog by double clicking on the layer in the legend and click on the Query Builder button on the tab See Section 5 4 for more information QGIS 1 1 0 User Guide 60 5 7 Select by query Figure 17 Query Builder A PostgreSQL Query Builder Table bc_hospitals in database bc on host localhost user stephan Fields o gid id authority name the_geom Values Cowichan District Hospital Dawson Creek and District Hospital Delta Hospital Eagle Ridge Hospital amp Health Ca East Kootenay Regional Hospital Fort St John General Hospital G R Baker Memorial Hospital Kelowna General Hospital Kitimat General Hospital Kootenay Boundary Regional Hos Sample All Operators T aat KE IN NOTIN A Ee mike ano or nor SQL where clause name LIKE General Cancel 5 7 Select by query With QGIS it is possible also to select features using a similar query builder interface to that used in 5 6 In the above section the purpose of the query builder is to only show features meeting the filter criteria as a virtual layer subset The purpose of the select by query function is to highlight all features that meet a part
117. elect location see Figure 26 and click Next Enter the name text for the new MAPSET Below in the wizard you see a list of existing MAPSETs and its owners 5When creating a new LOCATION GRASS automatically creates a special MAPSET called PERMANENT designed to store the core data for the project its default spatial extend and coordinate system definitions Neteler amp Mitasova 2008 2 QGIS 1 1 0 User Guide 89 9 GRASS GIS INTEGRATION 7 Click check out the summary to make sure it s all correct and click 9 4 Importing data into a GRASS LOCATION This Section gives an example how to import raster and vector data into the alaska GRASS LOCATION provided by the QGIS alaska dataset Therefore we use a landcover raster map landcover img and a vector GML File lakes gm1 from the QGIS alaska dataset 3 2 1 10 11 12 Start QGIS and make sure the GRASS plugin is loaded Inthe GRASS toolbar click the Open MAPSET icon to bring up the MAPSET wizard Select as GRASS database the folder grassdata in the QGIS alaska dataset as LOCATION alaska as MAPSET demo and click Now click the Open GRASS tools icon The GRASS Toolbox see Section 9 9 dialog appears To import the raster map landcover img click the module r in gdal in the Modules Tree tab This GRASS module allows to import GDAL supported raster files into a GRASS LOCATION The module dialog for r in g
118. em properties coer Opacity G Outline width CAS cree The print composer allows you to create several output formats and it is possible to define the reso lution print quality and paper size e The al Print icon allows to print the layout to a connected printer or as PDF or Postscript file depending on installed printer drivers QGIS 1 1 0 User Guide 107 10 PRINT COMPOSER e The Export as image icon exports the composer canvas in several image formats such as PNG BPM TIF JPG e The Export as SVG icon saves the print composer canvas as a SVG Scalable Vector Graphic Note Currently the SVG output is very basic This is not a QGIS problem but a problem of the underlaying Gt library This will hopefully be sorted out in future versions 10 1 6 Saving and loading a print composer layout With the de Save as template and Load from template icons you can save the current state of a print composer session as a qpt template and load the template again in another session QGIS 1 1 0 User Guide 108 11 QGIS Plugins QGIS has been designed with a plugin architecture This allows new features functions to be easily added to the application Many of the features in QGIS are actually implemented as core or external plugins e Core Plugins are maintained by the QGIS Development Team and are automatically part
119. en dragging the legend map divider 4 4 Measuring Measuring works within projected coordinate systems only e g UTM If the loaded map is defined with a geographic coordinate system latitude longitude the results from line or area measurements will be incorrect To fix this you need to set an appropriate map coordinate system See Section 8 4 4 1 Measure length and areas Mail QGIS is also able to measure real distances between given points according to a defined el lipsoid To configure this choose menu option Settings gt Options click on the tab and choose the appropriate ellipsoid The tool then allows you to click points on the map Each segment length shows up in the measure window and additionally the total length is printed To stop measuring click your right mouse button ul Areas can also be measured The window shows the accumulated area size in the measure window QGIS 1 1 0 User Guide 22 4 5 Projects Figure 3 Measure tools in action amp 24 76 mile 6 409 03 sq mile Close Close a Measure lines b Measure areas 4 5 Projects The state of your QGIS session is considered a Project QGIS works on one project at a time Settings are either considered as being per project or as a default for new projects see Section 4 7 QGIS can save the state of your workspace into a project file using the menu options gt i Save Project or gt Save Project As
120. eral Rendering Map tools Overlay Digitizing crs Locale Proxy When layer is loaded that has no coordinate reference system CRS Prompt for CRS Project wide default CRS will be used Global default CRS displayed below will be used proj longlat ellps WGS84 datum WGS84 no_defs Select Global Default Qe If you want to define the coordinate reference system for a certain layer without CRS information you can also do that in the General tab of the raster 6 3 4 and vector 5 4 1 properties dialog If your layer already has a CRS defined it will be displayed as shown in Figure 8 8 3 Define On The Fly OTF Projection QGIS does not have OTF projection enabled by default and this function is currently only supported for vector layers To use OTF projection you must open the Project Properties dialog select a CRS and activate the Enable on the fly projection checkbox There are two ways to open the dialog 1 Select s Project Properties from the Gnome OSX or Settings KDE Windows QGIS 1 1 0 User Guide 80 8 4 Custom Coordinate Reference System menu 2 Click on the projector icon in the lower right hand corner of the statusbar If you have already loaded a layer and want to enable OTF projection the best practice is to open the Coordinate Reference System tab of the Project Properties dialog select the CRS of the cur rently loaded layer
121. errs WAQRAQ RE eeORR OMDRPAOSTE gt aaneeutaG OAA v gt Layers IEA x alaska E EN climate N 6 GIs 2009 95 792274 3846279 Scale 1 3679369 9 9e Render li _ 5 5 Editing QGIS supports basic capabilities for editing vector geometries Before reading any further you should note that at this stage editing support is still preliminary Before performing any edits always make a backup of the dataset you are about to edit Note the procedure for editing GRASS layers is different see Section 9 7 for details QGIS 1 1 0 User Guide 49 5 WORKING WITH VECTOR DATA 5 5 1 Setting the Snapping Tolerance and Search Radius Before we can edit vertices it is very important to set the snapping tolerance and search radius to a value that allows us an optimal editing of the vector layer geometries Snapping tolerance Snapping tolerance is the distance QGIS uses to search for the closest vertex and or segment you are trying to connect when you set a new vertex or move an existing vertex If you aren t within the snap tolerance QGIS will leave the vertex where you release the mouse button instead of snapping it to an existing vertex and or segment 1 A general project wide snapping tolerance can be defined choosing Settings gt Options On Mac go to gt Preferences on Linux gt gt Options In the tab you can select between to vertex to segment or to ve
122. ers See Figure 54 The plugin requires the following parameters to be specified before running e Input vector layer Specify the input point vector layer from a list of loaded point layers e Interpolation attribute Select attribute column to be used for interpolation or enable the Use Z Coordinate checkbox to use the layers stored Z values e Interpolation Method Select interpolation method This can be either Triangulated Irregular Network TIN Y or Inverse Distance Weighted IDW Y e Number of columns rows Specify the number row and colums for the output raster file Output file Specify a name for the output raster file Figure 54 Interpolation Plugin A o Interpolation plugin x Input Input vector layer elevp gt Interpolation attribute ELEV 2 Output Interpolation method Inverse Distance Weighting IDW S an a Number of columns 300 PE 3 Number of rows 300 SS Output file qgis_sample_data csv elevp tiff lsa Q cancel lt 3 ok Using the plugin 1 Start QGIS and load an point vector layer e g elevp csv 2 Load the Interpolation plugin in the Plugin Manager see Section 11 1 1 and click on the Interpolation icon which appears in the QGIS toolbar menu The Interpolation plugin dialog appears as shown in Figure 54 QGIS 1 1 0 User Guide 134 12 9 Interpolation Plu
123. ertices of a Feature You can delete vertices by using the Delete Vertex icon on the toolbar Note it doesn t make sense to delete the vertex of a Point feature Delete the whole feature instead QGIS 1 1 0 User Guide 55 5 WORKING WITH VECTOR DATA Similarly a one vertex line or a two vertex polygon is also fairly useless and will lead to unpredictable results elsewhere in QGIS so don t do that Warning A vertex is identified for deletion as soon as you click the mouse near an eligible feature To undo you will need to toggle Editing off and then discard your changes Of course this will mean that other unsaved changes will be lost too Add Ring You can create ring polygons using the O Add Ring con in the toolbar This means inside an existing area it is possible to digitize further polygons that will occur as a whole so only the area in between the boundaries of the outer and inner polygons remain as a ring polygon Add Island You can add island polygons to a selected multipolygon The new island polygon has to be digitized outside the selected multipolygon Cutting Copying and Pasting Features Selected features can be cut copied and pasted between layers in the same QGIS project as long as destination layers are set to Toggle editing beforehand Features can also be pasted to external applications as text That is the features are
124. f any change b You must cause any work that you distribute or publish that in whole or in part contains or is derived from the Program or any part thereof to be licensed as a whole at no charge to all third parties under the terms of this License c If the modified program normally reads commands interactively when run you must cause it when started running for such interactive use in the most ordinary way to print or display an announcement including an appropriate copyright notice and a notice that there is no warranty or else saying that you provide a warranty and that users may redistribute the program under these conditions and telling the user how to view a copy of this License Exception if the Program itself is interactive but does not normally print such an announcement your work based on the Program is not required to print an announcement These requirements apply to the modified work as a whole If identifiable sections of that work are not derived from the Program and can be reasonably considered independent and separate works in themselves then this License and its terms do not apply to those sections when you distribute them as separate works But when you distribute the same sections as part of a whole which is a work based on the Program the distribution of the whole must be on the terms of this License whose permissions for other licensees extend to the entire whole and thus to each and every part regardless of who
125. ference system 72 crashes 109 CRS 72 data sample 9 Data management tools 133 data providers 113 delimited text 29 documentation 1 editing 49 an existing layer 51 copying features 56 creating a new layer 58 cutting features 56 icons 52 pasting features 56 saving changes 58 snap 58 working with the attribute table 58 EPSG 79 ESRI shapefiles 29 GDAL supported formats 151 Geometry tools 133 176 Geoprocessing tools 132 GRASS 85 attribute linkage 91 attribute storage 91 category settings 92 digitizing 91 digitizing tools 92 93 display results 98 edit permissions 95 loading data 86 region 96 display 96 editing 96 snapping tolerance 94 starting QGIS 85 symbology settings 94 table editing 95 toolbox 96 Browser 98 customize 99 modules 154 topology 91 vector data model 91 identify WMS 74 installation 9 layer visibility 17 layers initial visibility 21 layout toolbars 17 legend 17 license exception 174 GPL 169 main window 13 Index map overview 19 view 19 MapInfo MIF files 29 TAB files 29 measure 22 measure areas 22 measure line length 22 menus 14 MIF files 29 OGC Authentication 76 coordinate reference system 72 CRS 72 introduction 69 search 73 WMS client 69 OGR 29 supported formats 150 pan arrow keys 19 plugin georeferencer 114 grass toolbox 114 145 plugins 109 146 coordinate captu
126. ferenced data this can be either vector or raster data that contain the same ob jects features that you have on the raster that you want to georeference In this case you can enter the coordinates by clicking on the reference dataset loaded in QGIS map canvas The usual procedure for georeferencing an image involves selecting multiple points on the raster specifying their coordinates and choosing a relevant transformation type Based on the input param eters and data the plugin will compute the world file parameters The more coordinates you provide the better the result will be The first step is to start QGIS and load the Georeferencer Plugin see Section 11 1 1 and click on the a Georeferencer icon which appears in the QGIS toolbar menu The Georeferencer Plugin dialog appears as shown in Figure 48 For this example we are using a topo sheet of South Dakota from SDGS It can later be visualized together with the data from the GRASS spearfish60 location You can download the topo sheet here http grass osgeo org sampledata spearfish_toposheet tar gz Entering ground control points GCPs 1 To start georeferencing an unreferenced raster we must load it using the browse button The raster will show up in the main working area of the dialog Once the raster is loaded we can start to enter reference points 2 Using the Add Point button add points to the main working area and enter their coordi nates See Figure 4
127. for interacting with the map Each toolbar item has popup help available Hold your mouse over the item and a short description of the tool s purpose will be displayed Every menubar can be moved around according to your needs Additionally every menubar can be switched off using your right mouse button context menu holding the mouse over the toolbars Tip 3 RESTORING TOOLBARS If you have accidentally hidden all your toolbars you can get them back by choosing menu option Settings gt Tobas 4 2 3 Map Legend The map legend area is used to set the visibility and z ordering of layers Z ordering means that layers listed nearer the top of the legend are drawn over layers listed lower down in the legend The checkbox in each legend entry can be used to show or hide the layer Layers can be grouped in the legend window by adding a layer group and dragging layers into the group To do so move the mouse pointer to the legend window right click choose Add group A new folder appears Now drag the layers onto to the folder symbol It is then possible to toggle the visibility of all the layers in the group with one click To bring layers out of a group move the mouse pointer to the layer symbol right click and choose Make to toplevel item To give the folder a new name choose in the right click menu of the group QGIS 1 1 0 User Guide 17 4 FEATURES AT A GLANCE The content of the right mouse button context menu
128. ghtlick on the layer and choose Open Attribute Table from the dropdown menu This will open a new window which displays the attributes for every feature in the layer figure 16 Each column can be sorted by clicking on its header A small arrow indicates the sort order down ward pointing means descending values from the top row down upward pointing means ascend ing values from the top rown down For a simple selection by attributes on only one column the field can be used Select the field column from which the search should be performed from the dropdown menu and hit the button For more complex searches use the Advanced search EJ which will lauch the Search Query Builder described in Section 5 7 To show selected records only use the checkbox X Show selected records only Using the buttons at the bottom left of the window selected fields can be removed moved to the top of the table or the selection can be inverted Selected features can also be copied to the clipboard which can also be done with Ctrl C You can also zoom into the selected features on the map Toggle editing allows to edit single values of attributes QGIS 1 1 0 User Guide 59 5 WORKING WITH VECTOR DATA Figure 16 Attribute Table for Alaska layer amp MA Attnbute table alaska Ac cat A NAME AREA_MI 12 0 1 Alaska 0 168541 al 1 2 Alaska 0 209257 2 3 Alaska 0 837275 3 4 Alaska 0 322511 4 5 Alaska 1 46241 5 6 Al
129. gin 3 Select an input layer e g elevp Y and column e g ELEV for interpolation 4 Select an interpolation method e g Triangular interpolation 7 and specify the number of rows and columns e g 3663 cols and 1964 rows this is equivalent to a 1000 meter pixel resolution as well as the raster output filename e g elevation_tin 5 Click Ok 6 For the current example double click elevation_tin in the layer list to open the Raster Layer Properties dialog and select Pseudocolor j as Color Map in the Symbology tab Or you can define a new color table as described in Section 6 3 In Figure 55 you see the IDW interpolation result with a 366 cols x 196 rows 10 km resolution for the elevp csv data visualized using the Pseudocolor color table The processing only takes a few minutes and covers the northern part of Alaska Figure 55 Interpolation of elevp data using IDW method A Quantum GIS 1 1 0 Pan Unstable alaska File Edit View Layer Plugins Tools Help Layers ow TE Ly v alaska v s elevp Lo M Interpolation aca Overview EJ delas S j gt Ed RS 201326 7641461 Scale 1 25661701 Y T Render QGIS 1 1 0 User Guide 135 12 USING QGIS CORE PLUGINS 12 10 MapServer Export Plugin You can use QGIS to compose your map by adding and arranging layers
130. gs 14 3 BugTracker While the qgis users mailing list is useful for general how do do xyz in QGIS type questions you may wish to notify us about bugs in QGIS You can submit bug reports using the QGIS bug tracker at https trac osgeo org qgis When creating a new ticket for a bug please provide an email address where we can request additional information Please bear in mind that your bug may not always enjoy the priority you might hope for depending on its severity Some bugs may require significant developer effort to remedy and the manpower is not always available for this Feature requests can be submitted as well using the same ticket system as for bugs Please make sure to select the type enhancement If you have found a bug and fixed it yourself you can submit this patch also Again the lovely trac ticketsystem at https trac osgeo org qgis has this type as well Select patch from the type menu Someone of the developers will review it and apply it to QGIS Please don t be alarmed if your patch is not applied straight away developers may be tied up with other committments QGIS 1 1 0 User Guide 148 144 Blog 14 4 Blog The QGIS community also runs a weblog BLOG at http blog qgis org which has some in teresting articles for users and developers as well You are invited to contribute to the blog after registering yourself 14 5 Wiki Lastly we maintain a WIKI web site at http www agis org wiki
131. gularly This allows you to save your recent changes and Tip 16 CONCURRENT EDITS This version of QGIS does not track if somebody else is editing a feature at the same time as you The last person to save their edits wins br e 4 Y Es liz e Lole Le Split Features Move Features Move Vertex Add Vertex Delete Vertex Delete Selected Cut Features Copy Features Paste Features Adding Features Before you start adding features use the first navigate to the area of interest Then you can use the al pan and Q zoom in zoom out tools to of Capture point Capture line Capture polygon icons on the toolbar to put the QGIS cursor into digitizing mode For each feature you first digitize the geometry then enter its attributes To digitize the geometry left click on the map area to create the first point of your new feature QGIS 1 1 0 User Guide 53 5 WORKING WITH VECTOR DATA Tip 17 ZOOM IN BEFORE EDITING Before editing a layer you should zoom in to your area of interest This avoids waiting while all the vertex markers are rendered across the entire layer Tip 18 VERTEX MARKERS The current version of QGIS supports two kinds of vertex markers a semi transparent circle or a cross To change the mar
132. h that output contains areas where both layers intersect E Union Overlay layers such that output contains intersecting and non intersecting areas 6 Symetrical Overlay layers such that output contains those areas of the input and differ difference ence layers that do not intersect a Clip Overlay layers such that output contains areas that intersect the clip layer O Difference Overlay layers such that output contains areas not intersecting the clip layer B Dissolve Merge features based on input field All features with indentical input values are combined to form one single feature QGIS 1 1 0 User Guide 132 12 8 fTools Plugin Table 9 fTools Geometry tools Geometry tools available via the fTools plugin ometry columns Icon Tool Purpose y Check geometry Check polygons for intersections closed holes and fix node ordering Export Add ge Add vector layer geometry info to point XCOORD YCOORD line LENGTH or polygon AREA PERIMETER layer Polygon centroids Calculate the true centroids for each polygon in an input polygon layer Delaunay triangu lation Calculate and output as polygons the delaunay triangulation of an input point vector layer Simplify geometry Generalise lines or polygons with a modified Douglas Peucker algorithm Multipart to sin gleparts Convert multipart features to multiple singlepart features Creates simple polygons and lines
133. ible to add further attribute fields to the action Therefore you can add a to the end of the action text select another field and click on In this example there is just no other field available that would make sense to search for You can define multiple actions for a layer and each will show up in the Identify Results dialog You can also invoke actions from the attribute table by selecting a row and right clicking then choosing the action from the popup menu You can think of all kinds of uses for actions For example if you have a point layer containing locations of images or photos along with a file name you could create an action to launch a viewer to display the image You could also use actions to launch web based reports for an attribute field or combination of fields specifying them in the same way we did in our Google search example 5 4 6 Attributes Tab Within the Attributes tab the attributes of the selected dataset can be manipulated The buttons and Delete Column can be used when the dataset is in editing mode At the QGIS 1 1 0 User Guide 46 5 4 The Vector Properties Dialog moment only columns from PostGIS layers can be edited because this feature is not yet supported by the OGR library The Toggle editing mode button toggles this mode edit widget Within the Attributes tab you also find an edit widget and a value column These two columns can be used to define v
134. ick on one of these buttons to select the associated CRS Tip 33 PROJECT PROPERTIES DIALOG If you open the Project Properties dialog from the Gnome OSX or KDE Windows menu you must click on the Coordinate Reference System tab to view the CRS settings Opening the dialog from the projector icon will automatically bring the Coordinate Reference System tab to the front 8 4 Custom Coordinate Reference System If QGIS does not provide the coordinate reference system you need you can define a custom CRS To define a CRS select Custom CRS from the Gnome OSX or KDE Windows QGIS 1 1 0 User Guide 81 8 WORKING WITH PROJECTIONS Figure 23 Projection Dialog Fs Project Properties x General Coordinate Reference System CRS Enable on the fly CRS transformation Coordinate Reference System EPSG ID fe SWEREF99 16 30 3010 975 SWEREF99 17 15 3014 979 SWEREF99 18 00 3011 976 SWEREF99 16 45 3015 980 SWEREF99 20 15 3016 981 SWEREF99 21 45 3017 982 SWEREF99 23 15 3016 983 Sierra Leone 1924 New Colony Grid 2159 150 Sierra Leone 1924 New War Office Grid 2160 151 South Yemen Gauss Kruger zone 8 deprecated 2091 82 South Yemen Gauss Kruger zone 9 deprecated 2092 83 South Yemen Gauss Kruger zone 8 2395 364 South Yemen Gauss Kruger zone 9 2396 365 St Kitts 1955 British West Indies Grid 2005 6 St Lucia 1955 British West Indies Grid 2006 7
135. icular criteria Select by query can be used with all vector data providers To do a select by query on a loaded layer click on the button Open Table to open the attribute table of the layer Then click the button at the bottom This starts the Query Builder that allows to define a subset of a table and display it as described in Section 5 6 QGIS 1 1 0 User Guide 61 6 WORKING WITH RASTER DATA 6 Working with Raster Data This Section describes how to visualize and set raster layer properties QGIS supports a number of different raster formats Currently tested formats include e Arc Info Binary Grid Arc Info ASCII Grid e GRASS Raster e GeoTIFF e JPEG e Spatial Data Transfer Standard Grids with some limitations e USGS ASCII DEM e Erdas Imagine Because the raster implementation in QGIS is based on the GDAL library other raster formats implemented in GDAL are also likely to work if in doubt try to open a sample and see if it is supported You find more details about GDAL supported formats in Appendix A 2 or at http www gdal org formats_list html If you want to load GRASS raster data please refer to Section 9 2 6 1 What is raster data Raster data in GIS are matrices of discrete cells that represent features on above or below the earth s surface Each cell in the raster grid is the same size and cells are usually rectangular in QGIS they will always be rectangular Typical raster da
136. iew selecting the map element in the print composer and clicking the Update Preview button in the map tab see Figure 36 To move layers within the map element select the map element click the Move item content icon and move the layers within the map element frame with the left mouse button 10 1 2 Navigation tools For map navigation the print composer provides 4 general tools Zoom in Zoom out Zoom to full extend and 9 8 9 2 Refresh the view if you find the view in an inconsistent state QGIS 1 1 0 User Guide 104 10 1 Using Print Composer 10 1 3 Adding other elements to the Print Composer Besides adding a current QGIS map canvas to the Print Composer it is also possible to add position move and customize legend scalebar images and label elements Label and images To add a label or an image click the Add label PE or Add image con place the element with the left mouse button on the print composer canvas and position and customize their appearance in the tab Figure 37 Customize print composer label and images A General ltem General ltem Airports in Southwest Alaska Font Margin mm 1 00 S Composer item properties Color Frame Background Opacity Ff Outline width 0 30 Positio
137. iles you need a way to convert other GPS file formats to GPX This can be done for many formats using the free program GPSBabel which is available at http www gpsbabel org This program can also transfer GPS data between your computer and a QGIS 1 1 0 User Guide 127 12 USING QGIS CORE PLUGINS Figure 52 The GPS Tools dialog window A Load GPX file Import other file Download from GPS Upload to GPS GPX Conversions GPX is the GPS eXchange file format which is used to store information about waypoints routes and tracks Select a GPX file and then select the feature types that you want to load File qgis_sample_data gps national_monuments gpx Browse Feature types M Waypoints MV Routes V Tracks Help e Cancel ox GPS device QGIS uses GPSBabel to do these things so it is recommended that you install it How ever if you just want to load GPS data from GPX files you will not need it Version 1 2 3 of GPSBabel is known to work with QGIS but you should be able to use later versions without any problems 12 7 4 Importing GPS data To import GPS data from a file that is not a GPX file you use the tool Import other file in the GPS Tools dialog Here you select the file that you want to import and the file type which feature type you want to import from it where you want to store the converted GPX file and what the name of the new layer should be Note that not all GP
138. in Installer In order to download and install an external Python plugin click the menu gt Fetch Python Plugins The Plugin Installer window will appear figure 41 with the tab Plugins containing a list of all locally installed Python plugins as well as plugins available in remote repositories Each plugin can be either e not installed this means the plugin is available in the repository but is not installed yet In order to install it select the plugin from the list and click the Install plugin button QGIS 1 1 0 User Guide 110 11 1 Managing Plugins Figure 41 Installing external python plugins amp QGIS Python Plugin Installer x Plugins Repositories Options Filter QGIS Official Repository janystatus 4 Status Name Version Description notinstalled Zoom to Point 1 0 Zooms the map canvas to a coordinate you specify You can specify installed Plugin Installer 1 0 Downloads and installs QGIS python plugins Kil gt Install upgrade plugin Uninstall plugin The plugins will be installed to qgis python plugins Close e new this means that the plugin is newly available in the repository e installed this indicates that the plugin is already installed If it is also available in any repository the Reinstall plugin button will be enabled If the available version is older than the installed version the Downgrade plugin button will appear i
139. ing the normal SQL command CREATE INDEX afterwards as an extra step as described in the next section 5 2 5 5 2 5 Improving Performance Retrieving features from a PostgreSQL database can be time consuming especially over a network You can improve the drawing performance of PostgreSQL layers by ensuring that a spatial index exists on each layer in the database PostGIS supports creation of a GiST Generalized Search Tree index to speed up spatial searches of the data The syntax for creating a GiST index is CREATE INDEX indexname ON tablename USING GIST geometryfield GIST_GEOMETRY_OPS Note that for large tables creating the index can take a long time Once the index is created you should perform a VACUUM ANALYZE See the PostGIS documentation 6 for more information The following is an example of creating a GiST index gsherman madison current psql gis_data Welcome to psql 8 3 0 the PostgreSQL interactive terminal Type copyright for distribution terms h for help with SQL commands for help with psql commands g or terminate with semicolon to execute query q to quit gis_data CREATE INDEX sidx_alaska_lakes ON alaska_lakes gis_data USING GIST the_geom GIST_GEOMETRY_OPS CREATE INDEX gis_data VACUUM ANALYZE alaska_lakes 3GiST index information is taken from the PostGIS documentation available at http postgis refractions net QGIS 1 1 0 User Guide 37 5 WORKING WITH VECTOR DATA
140. ion type for the georeferencing process Depending on how many ground control point you have captured you may want to use different transformation algorithms Choice of transformation algorithm is also dependent on the type and quality of input data and the amount of geometric distortion that you are willing to introduce to final result QGIS 1 1 0 User Guide 123 12 USING QGIS CORE PLUGINS Figure 49 Add points to the raster image A Enter map coordinates x Enter X and Y coordinates which correspond with the selected point on the image Alternatively click the button with icon of a pencil and then click a corresponding point on map canvas of QGIS to fill in coordinates of that point 2 from map canvas Cancel Currently several algorithms are available k Linear Helmert Polynomial 1 Polynomial 2 Polynomial 3 Thin plate spline TPS O oa fF W N e The Linear algorithm is used to create a world file and is different from the other algorithms as it does not actually transform the raster This algorithm likely won t be sufficient if you are dealing with scanned material e The Helmert transformation performs simple scaling and rotation transformations e The Polynomial algorithms are among the most widely used algorithms for georeferencing and each one differs by the degree of distortion introduced to match source and destination ground control points The most widely used p
141. is intended to guarantee your freedom to share and change free software to make sure the software is free for all its users This General Public License applies to most of the Free Software Foundation s software and to any other program whose authors commit to using it Some other Free Software Foundation software is covered by the GNU Library General Public License instead You can apply it to your programs too When we speak of free software we are referring to freedom not price Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software and charge for this service if you wish that you receive source code or can get it if you want it that you can change the software or use pieces of it in new free programs and that you know you can do these things To protect your rights we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights These restrictions translate to certain responsibilities for you if you distribute copies of the software or if you modify it For example if you distribute copies of such a program whether gratis or for a fee you must give the recipients all the rights that you have You must make sure that they too receive or can get the source code And you must show them these terms so they know their rights We protect your rights with two steps 1 copyright the software and 2 offer you this license whi
142. istics for raster map layers r average Finds the average of values in a cover map within areas assigned the same category value in a user specified base map r median Finds the median of values in a cover map within areas assigned the same category value in a user specified base map r mode Finds the mode of values in a cover map within areas assigned the same category value in a user specified base map reproject raster im age r volume Calculates the volume of data clumps and produces a GRASS vector points map containing the calculated centroids of these clumps r surf area Surface area estimation for rasters r univar Calculates univariate statistics from the non null cells of a raster map r covar Outputs a covariance correlation matrix for user specified raster map layer s r regression line Calculates linear regression from two raster maps y a b x r coin Tabulates the mutual occurrence coincidence of categories for two raster map layers QGIS 1 1 0 User Guide 162 B 5 GRASS Toolbox vector data modules B 5 GRASS Toolbox vector data modules This Section lists all graphical dialogs in the GRASS Toolbox to work with and analyse vector data in a currently selected GRASS location and mapset Table 26 GRASS Toolbox Develop vector map modules Develop vector map modules in the GRASS Toolbox Module name Purpose v build all Rebuild topology of all vectors in the mapset v clean break Break lines a
143. isualizer If you take a look you ll notice that the export tool adds the metadata needed to enable our map file for WMS QGIS 1 1 0 User Guide 138 12 10 MapServer Export Plugin 12 10 3 Testing the Map File We can now test our work using the shp2img tool to create an image from the map file The shp2img utility is part of MapServer and FWTools To create an image from our map e Open a terminal window e If you didn t save your map file in your home directory change to the folder where you saved it e Run shp2img m qgisproject map o mapserver_test png and display the image This creates a PNG with all the layers included in the QGIS project file In addition the extent of the PNG will be the same as when we saved the project As you can see in Figure 58 all information except the airport symbols are included Figure 58 Test PNG created by shp2img with all MapServer Export layers A If you plan to use the map file to serve WMS requests you probably don t have to tweak anything If you plan to use it with a mapping template or a custom interface you may have a bit of manual work to do To see how easy it is to go from QGIS to serving maps on the web take a look at Christopher Schmidt s 5 minute flash video He used an older version of QGIS version 0 8 but the demo applies equally well to newer versions 8 Shttp openlayers org presentations mappingyourdata QGIS 1 1 0 User Guide 139 12 USING QGIS CORE PLUGI
144. ivates the mighty GRASS Toolbox Georeferencer Adding projection info to Rasterfiles Interpolation plugin Interpolation on base of vertices of a vector layer MapServer Export Plugin Export a saved QGIS project file to a MapServer map file North Arrow Displays a north arrow overlayed onto the map OGR Layer Converter Translate vector layers between OGR suported formats Oracle Georaster Access Oracle Spatial GeoRasters Plugin Installer Downloads and installs QGIS python plugins Si ridearerkstq lt F 60 SPIT Shapefile to PostgreSQL PostGIS Import Tool Qucik Print Quickly print a map with minimal effort Scalebar Draws a scale bar WFS Load and display WFS layer Tip 43 PLUGINS SETTINGS SAVED TO PROJECT When you save a qgs project any changes you have made to NorthArrow ScaleBar and Copyright plugins will be saved in the project and restored next time you load the project QGIS 1 1 0 User Guide 114 12 1 Delimited Text Plugin 12 1 Delimited Text Plugin The Delimited Text plugin allows you to load a delimited text file as a layer in QGIS Requirements To view a delimited text file as layer the text file must contain 1 A delimited header row of field names This must be the first line in the text file 2 The header row must contain an X and Y field These fields can have any name 3 The x and y coordinates must be specified as a number The c
145. k e NOAA Polar Orbiter Level 1b Data Set AVHRR e Erdas 7 x LAN and GIS e In Memory Raster e Vexcel MFF e Vexcel MFF2 e Atlantis MFF e Multi resolution Seamless Image Database MrSID e NITF e NetCDF e OGDI Bridge e Oracle Spatial Georaster e OGC Web Coverage Server e OGC Web Map Server e PCI aux Labelled e PCI Geomatics Database File e Portable Network Graphics png e Netpbm ppm pgm 15GRASS support is supplied by the QGIS GRASS data provider plugin QGIS 1 1 0 User Guide 152 A 2 GDAL Raster Formats USGS SDTS DEM CATD DDF e SAR CEOS e USGS ASCII DEM dem e X11 Pixmap xpm QGIS 1 1 0 User Guide 153 B GRASS TOOLBOX MODULES B GRASS Toolbox modules The GRASS Shell inside the GRASS Toolbox provides access to almost all more than 300 GRASS modules in command line modus To offer a more user friendly working environment about 200 of the available GRASS modules and functionalities are also provided by graphical dialogs B 1 GRASS Toolbox data import and export modules This Section lists all graphical dialogs in the GRASS Toolbox to import and export data into a currently selected GRASS location and mapset Table 13 GRASS Toolbox Raster and Image data import modules Raster and Image data import modules in the GRASS Toolbox Module name Purpose r in arc Convert an ESRI ARC INFO ascii raster file GRID into a binary raster
146. ker style choose from the menu and click on the Digitizing tab and select the appropriate entry For lines and polygons keep on left clicking for each additional point you wish to capture When you have finished adding points right click anywhere on the map area to confirm you have finished entering the geometry of that feature The attribute window will appear allowing you to enter the information for the new feature Figure 14 shows setting attributes for a fictitious new river in Alaska Figure 14 Enter Attribute Values Dialog after digitizing a new vector feature A Enter Attribute Values cat dbl F_CODEDESC txt NAM txt MyNewRiver F_CODE txt ShinyNewCode here Move Feature You can move features using the Move Feature icon on the toolbar Split Feature You can split features using the Split Features icon on the toolbar QGIS 1 1 0 User Guide 54 5 5 Editing Tip 19 ATTRIBUTE VALUE TYPES At least for shapefile editing the attribue types are validated during the entry Because of this it is not possible to enter a number into the text column in the dialog Enter Attribute Values or vica versa If you need to do so you should edit the attributes in a second step within the Attribute table dialog Editing Vertices of a Feature For both PostgreSQL PostGIS and shapefile based layers the vertices of features can
147. l be rendered each band representing the red green or blue component that will be used to create a color image Within both render types you can invert the color output using the Invert color map checkbox QGIS 1 1 0 User Guide 64 6 3 Raster Properties Dialog Single Band Rendering This selection offers you two possibilites to choose At first you can select which band you like to use for rendering if the dataset has more than one band The second option offers a selection of available colortables for rendering The following settings are available through the dropdownbox color map Grayscale Y where grayscale is the default setting Also available are e Pseudocolor e Freak Out e Colormap When selecting the entry color map Colormap Y the tab becomes available See more on that at chapter 6 3 3 QGIS can restrict the data displayed to only show cells whose values are within a given number of standard deviations of the mean for the layer This is useful when you have one or two cells with abnormally high values in a raster grid that are having a negative impact on the rendering of the raster This option is only available for pseudocolor images Three band color This selection offers you a wide range of options to modify the appereance of your rasterlayer For example you could switch color bands from the standard RGB order to something els
148. la o 6 44 02584842 Se Ree Sek A OS BEERS SS Od 9 2a Sampe SIN ape aa BE Se we ee A ds 10 4 Features at a Glance 12 Ai Staing and Stopping OGIS csee rego A ee ee ee e id a a 12 4 1 1 Command Line Options e uo 12 d2 WSO 2 ee Se dew be SES as e e ESSE 13 dzl Menmu Bar y ha feces hak ad Bae RR 14 422 Toolbars saco ee ee we ee a ew eee 17 4 23 MapLegend cisco Sheed be eS weak eS ERM EE A 17 Be Map VIEN o ova se koaa be da a a wd Bee a EEL AREER AR RS 19 4 2 5 Map Overview lt lt lt sg 44 88 eS Se A A ESS RS 19 426 CIWS Bar criada ORES AA RSE 20 A3 ON s sie ar the a ee oR aA Ew ARBRE a Oe we 20 4 3 1 Scale Dependent Rendering 21 4 3 2 Controlling Map Rendering e e eee eee 21 4A Measuring lt eh ee oe ER SESE Ee a E Aa ida a aa ode SES 22 4 4 1 Measure length and areas 22 ese cb ee ee ee we 22 A5 Re eze sk ee ee se ee eae Se eee fesse eae ee ae eS 23 QGIS 1 1 0 User Guide iii Contents AAA AI 24 Ae GUON 224434 6848200004 sd A 24 4 8 Spatial Bookmarks lt lt 200022222 a RAR 27 4 8 1 Creating a Bookmark 2 6 oe kk Sk sosa a A 27 4 6 2 Working with Bookmarks 2c 8 See ee wR ee eR ee 27 4 8 3 Zooming to a Bookmark lt a cocos cas BOA SERRE AS oe ee 27 464 Deleting a Bookmark 2 6 6 42445558 2 2b a ee EEO SE Hee ERS ES 28 5 Working with Vector Data 29 5S1 ESR Shap liles 22 sce ied ba sinda n wh Oe Bb Op e PSOE R hws 29 5 1 1 Lo
149. lbox Vector data import modules o 156 GRASS Toolbox Vector data export modules o o 156 GRASS Toolbox Data type conversion modules e 157 GRASS Toolbox Region and projection configuration modules 158 GRASS Toolbox Develop raster map modules o 159 GRASS Toolbox Raster color management modules 159 GRASS Toolbox Spatial raster analysis modules o o 160 GRASS Toolbox Surface management modules o 161 GRASS Toolbox Change raster category values and labels modules 161 GRASS Toolbox Hydrologic modelling modules 162 GRASS Toolbox Reports and statistic analysis modules 162 GRASS Toolbox Develop vector map modules 2 2 2 22000 163 GRASS Toolbox Database connection modules o 164 GRASS Toolbox Change vector field modules o 164 GRASS Toolbox Working with vector points modules 164 GRASS Toolbox Spatial vector and network analysis modules 165 GRASS Toolbox Vector update by other maps modules 165 GRASS Toolbox Vector report and statistic modules 165 GRASS Toolbox Imagery analysis modules o o 166 GRASS Toolbox Database Modules 167 GRASS Toolbox 3D Visualiz
150. le servers such as DEMIS and JPL OnEarth WMS servers act upon requests by the client e g QGIS for a raster map with a given extent set of layers symbolisation style and transparency The WMS server then consults its local data sources rasterizes the map and sends it back to the client in a raster format For QGIS this would typically be JPEG or PNG QGIS 1 1 0 User Guide 69 7 WORKING WITH OGC DATA WMS is generically a REST Representational State Transfer service rather than a fully blown Web Service As such you can actually take the URLs generated by QGIS and use them in a web browser to retrieve the same images that QGIS uses internally This can be useful for troubleshooting as there are several brands of WMS servers in the market and they all have their own interpretation of the WMS standard WMS layers can be added quite simply as long as you know the URL to access the WMS server you have a serviceable connection to that server and the server understands HTTP as the data transport mechanism 7 2 2 Selecting WMS Servers The first time you use the WMS feature there are no servers defined You can begin by clicking the Add WMS layer button inside the toolbar or through the Layer E Add WMS Layer menu The dialog Add Layer s from a Server for adding layers from the WMS server pops up Fortu nately you can add some servers to play with by clicking the Add default servers button
151. ll use to access the database e Password The password associated with your username that is required to access the database Now back on the main Oracle Spatial GeoRaster dialog window See Figure 61 use the drop down list to choose one connection and use the button to establish a connection You may also the connection by opening the previous dialog and making changes to the connection information or use the button to remove the connection from the drop down list 12 12 2 Selecting a GeoRaster Once a connection has been established the sub datasets window will show the names of all the tables that contains GeoRaster columns in that database in the format of a GDAL subdataset name Click on one of the listed subdatasets and then click on to choose the table name Now another list of subdatasets will show with the names of GeoRaster columns on that table This is QGIS 1 1 0 User Guide 142 12 12 Oracle GeoRaster Plugin Figure 60 Create Oracle connection dialog A Create Oracle Connection Connection Information Name example Cancel Database instance orcl Username scott Password rr y Save Password usually a short list since most users will not have more than one or two GeoRaster columns on the same table Click on one of the listed subdatasets and then click on to choose one of the the ta ble column combination The dialog will now show all the rows that contains GeoRaster objects Note that the su
152. lor transformation function his rgb Hue Intensity Saturation HIS to Red Green Blue RGB raster map color transform function i landsat rgb Auto balancing of colors for LANDSAT images i fusion brovey Brovey transform to merge multispectral and high res pancromatic channels i ZC Zero crossing edge detection raster function for image processing mfilter i tasscap4 Tasseled Cap Kauth Thomas transformation for LANDSAT TM 4 data i tasscap5 Tasseled Cap Kauth Thomas transformation for LANDSAT TM 5 data i tasscap7 Tasseled Cap Kauth Thomas transformation for LANDSAT TM 7 data i fft Fast fourier transform FFT for image processing i ifft Inverse fast fourier transform for image processing r describe Prints terse list of category values found in a raster map layer r bitpattern Compares bit patterns with a raster map r kappa Calculate error matrix and kappa parameter for accuracy assessment of classification result i oif Calculates optimal index factor table for landsat tm bands QGIS 1 1 0 User Guide 166 B 7 GRASS Toolbox database modules B 7 GRASS Toolbox database modules This Section lists all graphical dialogs in the GRASS Toolbox to manage connect and work with internal and external databases Working with spatial external databases is enabled via OGR and not covered by these modules Table 34 GRASS Toolbox Database modules Database management and anal
153. lve Dissolves boundaries between adjacent areas v drape Convert 2D vector to 3D vector by sampling of elevation raster v transform Performs an affine transformation on a vector map v proj Allows projection conversion of vector files v support Updates vector map metadata generalize Vector based generalization QGIS 1 1 0 User Guide 163 B GRASS TOOLBOX MODULES Table 27 GRASS Toolbox Database connection modules Database connection modules in the GRASS Toolbox Module name Purpose v db connect Connect a vector to database v db sconnect Disconnect a vector from database v db what connect Set Show database connection for a vector Table 28 GRASS Toolbox Change vector field modules Change vector field modules in the GRASS Toolbox Module name Purpose v category add Add elements to layer ALL elements of the selected layer type v category del Delete category values v category sum Add a value to the current category values v reclass file Reclass category values using a rules file v reclass attr Reclass category values using a column attribute integer positive Table 29 GRASS Toolbox Working with vector points modules Working with vector points modules in the GRASS Toolbox Module name Purpose v in region Create new vector area map with current region extent v mkgrid region Create grid in cu
154. map layer r in ascii Convert an ASCII raster text file into a binary raster map layer r in aster Georeferencing rectification and import of Terra ASTER imagery and relative DEM s using gdalwarp r in gdal Import GDAL supported raster file into a GRASS binary raster map layer r in gdal loc Import GDAL supported raster file into a GRASS binary raster map layer and create a fitted location r in gdal qgis Import loaded raster into a GRASS binary raster map layer r in gdal qgis loc Import loaded raster file into a GRASS binary raster map layer and create a fitted location r in gridatb Imports GRIDATB FOR map file TOPMODEL into GRASS raster map r in mat Import a binary MAT File v4 to a GRASS raster r in poly Create raster maps from ascii polygon line data files in the current di rectory r in srtm Import SRTM HGT files into GRASS i in spotvgt Import of SPOT VGT NDVI file into a raster map QGIS 1 1 0 User Guide 154 B 1 GRASS Toolbox data import and export modules Table 14 GRASS Toolbox Raster and Image data export modules Raster and Image data export modules in the GRASS Toolbox Module name Purpose r out gdal gtiff Export raster layer to Geo TIFF r out arc Converts a raster map layer into an ESRI ARCGRID file r gridatb Exports GRASS raster map to GRIDATB FOR map file TOPMODEL r out mat Exports a GRASS raster to a binary MAT File r out bin Exports a GRASS raster to a bin
155. mises to introduce all sorts of other features but many will be based on a combination of maps and analysis For example you have a cell phone that tracks your geographic location If you have the right software your phone can tell you what kind of restaurants are within walking distance While this is a novel application of geospatial technology it is essentially doing geospatial data analysis and listing the results for you 2 1 Why is all this so new Well its not There are many new hardware devices that are enabling mobile geospatial services Many open source geospatial applications are also available but the existence of geospatially fo This chapter is by Tyler Mitchell http www oreillynet com pub wlg 7053 and used under the Creative Com mons License Tyler is the author of Web Mapping Illustrated published by O Reilly 2005 QGIS 1 1 0 User Guide 6 2 1 Whyis all this so new cused hardware and software is nothing new Global positioning system GPS receivers are be coming commonplace but have been used in various industries for more than a decade Likewise desktop mapping and analysis tools have also been a major commercial market primarily focused on industries such as natural resource management What is new is how the latest hardware and software is being applied and who is applying it Tra ditional users of mapping and analysis tools were highly trained GIS Analysts or digital mapping technicians trai
156. n x Frame Search directories Add Remove usr local share qgis svg north_arroy v Preview TOMATES a z orth_arrows NorthArrow2 svg Browse Width 20 Height 120 Rotation 0 00 gt Composer item properties Color Frame Background Opacity Outline width 0 30 _ E Position Frame a label item tab b image item tab QGIS 1 1 0 User Guide 105 10 PRINT COMPOSER Legend and scalebar To add a map legend or a scalebar click the Add new legend or Add new scalebar icon place the element with the left mouse button on the print composer canvas and position and customize their appearance in the tab Figure 38 Customize print composer legend and scalebar General ltem Segment Map units per A i size map 300000001 SP Unts per 000 00 t General Item AD bar unit Number of General aa Segments left 0 piel Legend Style Single Box Map Map 0 x Font dies eae rai Height mm 5 2 Line width 1 00 2 Symbol width 7 00 Symbol height 4 00 la Label space 3 00 Box space 1 00 Layer space 3 00 Symbol space 2 00 con label space 2 00 gt Box space 2 00 2 Unit label miles Font Color Legend items Composer item properties down up remove edit updat
157. n be freely modified You should have received a full copy of the license with your copy of QGIS and you also can find it in Appendix C Tip 1 UP TO DATE DOCUMENTATION The latest version of this document can always be found at http download osgeo org qgis doc manual or in the documentation area of the QGIS website at http qgis osgeo org documentation 1 1 Features QGIS offers many common GIS functionalities provided by core features and plugins As a short summary they are presented in six categories to gain a first insight View data You can view and overlay vector and raster data in different formats and projections without conver sion to an internal or common format Supported formats include e spatially enabled PostgreSQL tables using PostGIS vector formats supported by the installed OGR library including ESRI shapefiles MapInfo SDTS and GML e Raster and imagery formats supported by the installed GDAL Geospatial Data Abstraction Library library such as GeoTiff Erdas Img Arclnfo Ascii Grid JPEG PNG OGR supported database formats such as Oracle or mySQL are not yet supported in QGIS QGIS 1 1 0 User Guide 1 1 FOREWORD SpatiaLite databases see Section 5 3 GRASS raster and vector data from GRASS databases location mapset Online spatial data served as OGC compliant Web Map Service WMS or Web Feature Service WFS Explore data and compose maps You can compose maps and interac
158. nd Not yet used in this version of QGIS Can Identify Whether or not this layer will return any results when the Identify tool is used on it QGIS 1 1 0 User Guide 74 7 2 WMS Client Can be Transparent Whether or not this layer can be rendered with transparency This version of QGIS will always use transparency if this is Yes and the image encoding sup ports transparency Can Zoom In Whether or not this layer can be zoomed in by the server This version of QGIS assumes all WMS layers have this set to Yes Deficient layers may be rendered strangely Cascade Count WMS servers can act as a proxy to other WMS servers to get the raster data for a layer This entry shows how many times the request for this layer is forwarded to peer WMS servers for a result Fixed Width Fixed Height Whether or not this layer has fixed source pixel dimensions This version of QGIS assumes all WMS layers have this set to nothing Deficient layers may be rendered strangely WGS 84 Bounding Box The bounding box of the layer in WGS 84 coordinates Some WMS servers do not set this correctly e g UTM coordinates are used instead If this is the case then the initial view of this layer may be rendered with a very zoomed out appearance by QGIS The WMS webmaster should be informed of this error which they may know as the WMS XML elements LatLonBoundingBox EX_GeographicBoundingBox or the CRS 84 BoundingBox
159. ned to use CAD like tools Now the processing capabilities of home PCs and open source software OSS packages have enabled an army of hobbyists professionals web developers etc to interact with geospatial data The learning curve has come down The costs have come down The amount of geospatial technology saturation has increased How is geospatial data stored In a nutshell there are two types of geospatial data in widespread use today This is in addition to traditional tabular data that is also widely used by geospatial applications 2 1 1 Raster Data One type of geospatial data is called raster data or simply a raster The most easily recognised form of raster data is digital satellite imagery or air photos Elevation shading or digital elevation models are also typically represented as raster data Any type of map feature can be represented as raster data but there are limitations A raster is a regular grid made up of cells or in the case of imagery pixels They have a fixed number of rows and columns Each cell has a numeric value and has a certain geographic size e g 30x30 meters in size Multiple overlapping rasters are used to represent images using more than one colour value i e one raster for each set of red green and blue values is combined to create a colour image Satellite imagery also represents data in multiple bands Each band is essentially a separate spatially overlapping raster where each band holds value
160. ng points r cross Create a cross product of the category value from multiple raster map layers r series Makes each output cell a function of the values assigned to the corre sponding cells in the output raster map layers r patch Create a new raster map by combining other raster maps r statistics Category or object oriented statistics r cost Outputs a raster map layer showing the cumulative cost of moving be tween different geographic locations on an input raster map layer whose cell category values represent cost r drain Traces a flow through an elevation model on a raster map layer r shaded relief Create shaded map r slope aspect slope Generate slope map from DEM digital elevation model r slope aspect aspect Generate aspect map from DEM digital elevation model r param scale Extracts terrain parameters from a DEM r texture Generate images with textural features from a raster map first serie of indices r texture bis Generate images with textural features from a raster map Second serie of indices r los Line of sigth raster analysis r clump Recategorizes into unique categories contiguous cells r grow Generates a raster map layer with contiguous areas grown by one cell r thin Thin no zero cells that denote line features QGIS 1 1 0 User Guide 160 B 4 GRASS Toolbox raster data modules Table 22 GRASS Toolbox Surface management modules Surface m
161. nn a a a a a a 60 5 7 Select y GUEY cac ehhh Se ara o a a a a a a a 61 6 Working with Raster Data 62 sl ANALISIS dala seare bee hema a PE eee he ee oe aR 62 6 2 Loading raster data in QGIS es 62 6 3 Raster Properties Dialog coso sr debe a 63 QGIS 1 1 0 User Guide iv Contents 631 Symbology Tab ce ca aarda A A 6 3 2 Transparency Tab 15 0 ic ei 4 64 28 Co OIM 020500 da e a en S4 OS 634 General Tab 00d A 6 3 5 Metadata Tab ose ce ek srt animi dya 6 3 6 Pyramids lab lt gt s ssc ced carora a ws ar Histogram TaD o s ocer 46 aaa we Be e 7 Working with OGC Data 7 1 T2 7 3 y des cu EA a A A Oe See Le a 7 2 1 Overview of WMS Support 7 2 2 Selecting WMS Servers o 7 2 3 Loading WMS Layers 64666 ee ee eee ene 7 2 4 Server Search 2 ae ke kek RAR eh bee eS 7 2 5 Using the Identify TOO ceros 7 2 6 Viewing PrOpeies 2 2 2 604 28885444448 804 7 2 7 WMS Client Limitations WFS Client 604d ee docs Ca ek Ee tae oe ok ROG rE 7 3 1 Loading a WFS Layer co wi Pa ee be ew sra 8 Working with Projections 8 1 8 2 8 3 8 4 Overview of Projection Support Specifying a Projection cc ica ae Define On The Fly OTF Projection Custom Coordinate Reference System 9 GRASS GIS Integration 9 1 9 2 9 3 9 4 9 5 9 6 gr 9 8 9 9 Starting the GRASS plugin aoaaa L
162. not supported at this time To start the WFS plugin you need to open Plugins gt Q Plugin Manager activate the x WFS plugin checkbox and click A new Add WFS Layer icon appears next to the WMS icon Click on it to open the dialog In General adding a WFS layer is very similar to the procedure used with WMS The difference is there are no default servers defined so we have to add our own 7 3 1 Loading a WFS Layer As an example we use the DM Solutions WFS server and display a layer The URL is http www2 dmsolutions ca cgi bin mswfs_gmap VERSION 1 0 0 amp SERVICE wf s amp REQUEST GetCapabilities 1 Make sure the WFS plugin is loaded if not open the Plugin Manager and load it Click on the Add WFS Layer tool on the plugins toolbar 3 Click on 4 Enter Name DM Solutions as the name 5 Enter the URL see previous page 6 Click 7 Choose Server Connections DM Solutions Y from the drop down box 8 Click Connect 9 Wait for the list of layers to be populated 10 Click on the Canadian Land layer N QGIS 1 1 0 User Guide 76 7 3 WES Client 11 Click to add the layer to the map 12 Wait patiently for the features to appear Note that the WFS plugin also recognizes the proxy settings you have set in your preferences Figure 21 Adding a WFS layer amp Bell WES bayer irom Sevel Server Connectio
163. ns DM Solutions WFS server Connect New Delete Name Abstract Canadian Land prov_land US Land land_fn Parks park US Lakes drain_fn drainage Provincial Bor prow_bound Federal Limit fedlimit Railroads rail Roads road Cities popplace Grid grid r Coordinate Reference System EPSG 42304 Help Ol Cancel You ll notice the download progress is visualized in the left bottom of the QGIS main window Once the layer is loaded you can identify and select a province or two and view the attribute table Remember this plugin works best with UMN MapServer WFS servers It still could be that you might experience random behavior and crashes You can look forward to improvements in a future version of the plugin This means that only WFS 1 0 0 is supported At this point there have not been many test against over WFS versions implemented in other WFS servers If you encounter problems with any other WFS server please do not hesitate to contacting the development team Please refer to Section 14 for further information about the mailinglists Tip 31 FINDING WFS SERVERS You can find additional WFS servers by using Google or your favorite search engine There are a number of lists with public URLs some of them maintained and some not QGIS 1 1 0 User Guide 77 7 WORKING WITH OGC DATA Tip 32 ACCESSING SECURE WFS SERVERS Within the dialog Create a new WFS connection
164. nstead e upgradeable this means that the plugin is installed but there is an updated version available In this case the Upgrade plugin button will be enabled e invalid this means that the plugin is installed but is unavailable or broken The reason will be explained in the plugin description field Plugins tab To install a plugin select it from the list and click the Install plugin button The plugin is installed in its own directory e A Linux and other unices share qgis python plugins home USERNAME qgis python plugins QGIS 1 1 0 User Guide 111 11 QGIS PLUGINS e X Mac OS x Contents MacOS share qgis python plugins Users SUSERNAME qgis python plugins R Windows C Program Files QGIS python plugins C Documents and Settings BUSERNAME qgis python plugins If the installation is successful a confirmation message will appear telling you to go to gt Manage Plugins to load the newly installed plugin If the installation fails the reason for the failure will be displayed in a warning dialog Most often errors are the result of connection problems and or missing Python modules In the former case you will likely need to wait before trying the install again in the latter case you should install the missing modules relevant to your operating system prior to using the plugin For Linux most required m modules should be available via a package manager AL For install ins
165. oad tool o a aaa aaa e eee 129 54 Interpolation Plugin D e e as a 134 55 Interpolation of elevp data using IDW method IN 135 56 Arrange raster and vector layers for QGIS project file rr ae 136 57 Export to MapServer Dialog gee fe eae oe eee 137 58 Test PNG created by shp2img with all MapServer Export layers a ad 139 59 OGR Layer Converter Plugin SI 140 60 Create Oracle connection dialog Dn oe Stn es a race Ge ee 143 61 Select Oracle GeoRaster dialog GO ees Be eye re E 144 QGIS 1 1 0 User Guide ix List of Tables List of Tables ON O 01 ADN WBWWWWWWONMNNHNHNNNHNNNNZFZFE a oo oo eo cm md aH O MNOoaRWN HK ODAANDAKRPWANHI ODODADAAN OA KRWN O PostGIS Connection Parameters o e eo 33 WMS Connection Parameters 4424643565805 a eee ae eX 70 GRASS Digitizing Tools o oo nin a A eee ews 93 Pint Composer TOOS AMA 101 QGIS Core Plugins s s 00 a eo e s aa ae ae e a 114 TIOS Analysis tools 2020 a oeo LOS A a a e eee eee LES aa aa 131 fTools Research tools nanana e a ee eS a 132 fools Geoprocessing tools lt s roe tona ai a A de a A a de 132 fTools Geometry tools aii RR AAA oe 133 fTools Data management tools o oo a 133 ther Core PINES ec a a ee ee ed ROR RR tds eS 145 Current moderated external QGIS Plugins oosa o 146 GRASS Toolbox Raster and Image data import modules 154 GRASS Toolbox Raster and Image data export modules 155 GRASS Too
166. oading GRASS raster and vectorlayers GRASS LOCATION and MAPSET 9 3 1 Creating a new GRASS LOCATION 9 3 2 Adding a new MAPSET o Importing data into a GRASS LOCATION The GRASS vector data model Creating a new GRASS vector layer Digitizing and editing a GRASS vector layer The GRASS region tool 6 kn ee oa O OR The GRASS toolbox A Se eee ECE aS 9 9 1 Working with GRASS modules 9 9 2 Working with the GRASS LOCATION browser 9 9 3 Customizing the GRASS Toolbox QGIS 1 1 0 User Guide Contents 10 Print Composer 10 1 Using Print Composer 10 1 1 Adding a current QGIS map canvas to the Print Composer 10 1 2 Navigation tools 10 1 3 Adding other elements to the Print Composer 10 1 4 Raise lower and align elements 0 e 10 1 5 Creating Output 10 1 6 Saving and loading a print composer layout 0050 11 QGIS Plugins 11 1 Managing Plugins 11 1 1 Leading a QGIS Gore Plugin wk ete ee ea Re ee 11 1 2 Loading an external OGIS PIU AA e kB ed ho ee eA eS 11 1 3 Using the QGIS Python Plugin Installer 11 2 Data Providers 12 Using QGIS Core Plugins 12 1 Delimited Text Plugin 12 2 Coordinate Capture Plugin 12 3 Decorations Plugins 1
167. of every QGIS distribution They are written in one of two languages C or Python More information about core plugins are provided in Section 12 e External Plugins are currently all written in Python They are stored in external repositories and maintained by the individual authors They can be added to QGIS using the Plugin Installer More information about external plugins are provided in Section 13 11 1 Managing Plugins Managing plugins in general means loading or unloading them using the Plugin Manager External plugins first need to be installed using the Plugin Installer 11 1 1 Loading a QGIS Core Plugin Loading a QGIS Core Plugin is done from the main menu Plugins gt Manage Plugins The Plugin Manager lists all the available plugins and their status loaded or unloaded including all core plugins and all external plugins that have been added using the Plugin Installer see Section 13 Those plugins that are already loaded have a check mark to the left of their name Figure 40 shows the Plugin Manager dialog To enable a particular plugin click on the checkbox to the left of the plugin name and click OK When you exit the application a list of loaded plugins is retained and the next time you run QGIS these plugins are automatically loaded Tip 41 CRASHING PLUGINS If you find that QGIS crashes on startup a plugin may be at fault You can stop all plugins from loading by editing your stored settings file se
168. of classes 15 Bl you need and press the button Classify Currently only one Classification mode Equal Interval Y is supported 6 3 4 General Tab The tab displays basic information about the selected raster including the layer source and display name in the legend which can be modified This tab also shows a thumbnail of the layer its legend symbol and the palette Additionally scale dependent visability can be set in this tab You need to check the checkbox and set an appropriate scale where your data will be displayed in the map canvas Also the spatial reference system is printed here as a PROJ 4 string This can be modified by hitting the button 6 3 5 Metadata Tab The Metadata tab displays a wealth of information about the raster layer including statistics about each band in the current raster layer Statistics are gathered on a need to know basis so it may well be that a given layers statistics have not yet been collected This tab is mainly for information You cannot change any values printed inside this tab To update the statistics you need to change to tab and press the button on the bottom right see ch 6 3 7 6 3 6 Pyramids Tab Large resolution raster layers can slow navigation in QGIS By creating lower resolution copies of the data pyramids performance can be considerably improved as QGIS selects the most suitable resolution to use depen
169. of the map width Define Ellipsoid for distance calculations e Define Rubberband Color for Measure Tools e Define Mouse wheel action Zoom Zoom and recenter Zoom to mouse cursor Nothing e Define Zoom factor for wheel mouse Digitizing Tab Define Rubberband Color and line width for Digitizing Define default snap mode to vertex to segment to vertex and segment Define default snapping tolerance in layer units e Define search radius for vertex edits in layer units e Define vertex marker style Cross or semi transparent circle CRS Tab e x Prompt for Coordinate Reference System CRS e x Project wide default Coordinate Reference System CRS will be used e x Global default Coordinate Reference System CRS displayed below will be used Select global default Coordinate Reference System CRS Locale Tab e Overwrite system locale and use defined locale instead e Information about active system locale Proxy Tab Use proxy for web access and define host port user and password e Set the Proxy type according to your needs QGIS 1 1 0 User Guide 25 4 FEATURES AT A GLANCE Default Proxy Proxy is determined based on the application proxy set using Socks5Proxy Generic proxy for any kind of connection Supports TCP UDP binding to a port incoming connections and authentication HttpProxy Implemented using the CONN
170. ogether in a certain order like drawing a line from Point x1 y1 to Point x2 y2 and so on These parts between each point are considered line segments They have a length and the line can be said to have a direction based on the order of the points Technically a line is a single pair of coordinates connected together whereas a line string is multiple lines connected together 3 Polygons When lines are strung together by more than two points with the last point being at the same location as the first we call this a polygon A triangle circle rectangle etc are all polygons The key feature of polygons is that there is a fixed area within them QGIS 1 1 0 User Guide 8 3 Getting Started This chapter gives a quick overview of installing QGIS some sample data from the QGIS web page and running a first and simple session visualizing raster and vector layers 3 1 Installation Installation of QGIS is very simple Standard installer packages are available for MS Windows and Mac OS X For many flavors of GNU Linux binary packages rpm and deb or software repositories to add to your installation manager are provided Get the latest information on binary packages at the QGIS website at http qgis osgeo org download Installation from source If you need to build QGIS from source please refer to the coding and compiling guide available at http qgis osgeo org documentation The installation instructions are also distributed wi
171. ols also work with raster and vector layers in another MAPSET 9 9 3 Customizing the GRASS Toolbox Nearly all GRASS modules can be added to the GRASS toolbox A XML interface is provided to parse the pretty simple XML files which configures the modules appearance and parameters inside the toolbox A sample XML file for generating the module v buffer v buffer qgm looks like this QGIS 1 1 0 User Guide 99 9 GRASS GIS INTEGRATION lt xml version 1 0 encoding UTF 8 gt lt DOCTYPE qgisgrassmodule SYSTEM http mrcc com qgisgrassmodule dtd gt lt qgisgrassmodule label Vector buffer module v buffer gt lt option key input typeoption type layeroption layer gt lt option key buffer gt lt option key output gt lt qgisgrassmodule gt The parser reads this definition and creates a new tab inside the toolbox when you select the module A more detailed description for adding new modules changing the modules group etc can be found on the QGIS wiki at http wiki qgis org qgiswiki Adding_New_Tools_to_the_GRASS_Toolbox QGIS 1 1 0 User Guide 100 10 Print Composer The print composer provides growing layout and printing capabilities lt allows you to add elements such as the QGIS map canvas legend scalebar images and text labels You can size group align and position each element and adjust the properties to create your layout The layout can be printed also to Postscript
172. olynomial algorithm is the second order polynomial transformation which allows some curvature First order polynomial transformation affine preserves colliniarity and allows scaling translation and rotation only e The Thin plate spline TPS algorithm is a more modern georeferencing method which is able to introduce local deformations in the data This algorithm is useful when very low quality originals are being georeferenced Running the transformation 1 When the GCPs have been collected and the transformation has been chosen press either to create a new raster or Create and load layer to automatically add the new raster QGIS 1 1 0 User Guide 124 12 5 Georeferencer Plugin to the layer list 2 A warning message will appear that will inform you that a new raster in GeoTIFF format will be created 3 After hitting OK you will also be asked to choose a resampling method There are three meth ods available a Nearest neighbour b Linear c Cubic Tip 44 CHOOSING THE RESAMPLING METHOD The type of resampling you choose will likely depending on your input data and the ultimate objective of the exercise If you don t want to change statistics of the image you might want to choose Nearest neighbour whereas a Cubic resampling will likely provide a more smoothed result QGIS 1 1 0 User Guide 125 12 USING QGIS CORE PLUGINS 12 6 Quick Print Plugin The 5 Quick Print Figure 51
173. on on importing data into the database To load a layer from PostGIS perform the following steps e If the Add PostGIS Table s dialog is not already open click on the e Add a PostGIS Layer toolbar button Choose the connection from the drop down list and click Find the layer you wish to add in the list of available layers Select it by clicking on it You can select multiple layers by holding down the key while clicking See Section 5 6 for information on using the PostgreSQL Query Builder to further define the layer Click on the button to add the layer to the map 5 2 3 Some details about PostgreSQL layers This section contains some details on how QGIS accesses PostgreSQL layers Most of the time QGIS should simply provide you with a list of database tables that can be loaded and load them on QGIS 1 1 0 User Guide 34 5 2 PostGIS Layers Tip 10 POSTGIS LAYERS Normally a PostGIS layer is defined by an entry in the geometry_columns table From version 1 0 0 on QGIS can load layers that do not have an entry in the geometry_columns table This includes both tables and views Defining a spatial view provides a powerful means to visualize your data Refer to your PostgreSQL manual for information on creating views request However if you have trouble loading a PostgreSQL table into QGIS the information below may help you understand any QGIS messages and give you direction on changing the P
174. oo ooo 94 29 GRASS Digitizing Settings Tab D ooo ooo ooo 94 30 GRASS Digitizing Symbolog Tab A 95 31 GRASS Digitizing Table Tab 2 oo ooo o 95 32 GRASS Toolbox and searchable Modules List A o o o 97 33 GRASS Toolbox Module Dialogs B o ooo 97 34 GRASS LOCATION browser 2 ooo 99 35 Print Composer SA 102 36 Print Composer map item tab content II ee E E 104 37 Customize print composer label and images ri e e E 105 38 Customize print composer legend and scalebar Dro ea es oe e 106 39 Print Composer with map view legend scalebar and text added N 107 40 Plugin Manager Ds a o a ici cios Se e 110 QGIS 1 1 0 User Guide viii List of Figures 41 Installing external python plugins Des ia he ees 111 42 Delimited Text Dialog o o ee 116 43 Coordinate Cature Plugin grace et ee eee E ecg 2 117 44 Copyright Label Plugin coco weg bd whee S ewan keds bees ee eas 118 45 North Arrow Plugin 0 0 00 00 ce ee 119 46 Scale Bar Plugin ee ae ek ae a ae ee a ee eee ere eee 120 47 Dxf2Shape Converter Plugin Sokig hnd Bog Boe tent Bm Ecdve conned donee 64g Boe 121 48 Georeferencer Plugin Dialog De pro bo ee we Gee fe ee Sak 123 49 Add points to the raster image A Ht See es Oa ee ee BE es 124 50 Quick Print Dialog Qo ee 126 51 Quick Print result as DIN A4 PDF using the alaska sample dataset 126 52 The GPS Tools dialog window 128 53 The downl
175. oordinate system is not important As an example of a valid text file we import the elevation point data file elevp csv coming with the QGIS sample dataset See Section 3 2 X Y ELEV 300120 7689960 13 654360 7562040 52 1640 7512840 3 leew Some items of note about the text file are 1 The example text file uses as delimiter Any character can be used to delimit the fields The first row is the header row It contains the fields X Y and ELEV No quotes are used to delimit text fields The x coordinates are contained in the X field a A WwW PN The y coordinates are contained in the Y field Using the Plugin To use the plugin you must first enable it as described in Section 11 1 Click the new toolbar icon En Add Delimited Text Layer to open the Delimited Text dialog as shown in Figure 42 First select the file e g qgis_sample_data csv elevp csv to import by clicking on the button Once the file is selected the plugin attempts to parse the file using the last used delimiter in this case a semi colon To properly parse the file it is important to select the correct delimiter To change the delimiter to tab use t this is a regular expression for the tab character After changing the delimiter click QGIS 1 1 0 User Guide 115 12 USING QGIS CORE PLUGINS Figure 42 Delimited Text Dialog amp Create a Layer from a Delimited Text File x Delimited Text Layer Use th
176. oprocessing Tools as well as several useful Data Management Tools fTools functions Tables 6 through 10 list the functions available via the fTools plugin along with a brief descrip tion of each function For further information on an individual fTools function please click the fTools Information menu item in the menu Table 6 fTools Analysis tools Analysis tools available via the fTools plugin O 5 Tool Purpose Distance Matrix Measure distances between two point layers and output results as a Square distance matrix b Linear distance matrix or c Summary of distances Can limit distances to the k nearest features Sum line length Calculate the total sum of line lengths for each polygon of a polygon vector layer Points in polygon Count the number of points that occur in each polygon of an input poly gon vector layer List unique values List all unique values in an input vector layer field Basic statistic Compute basic statistics mean std dev N sum CV on an input field lil A R A Nearest Neighbor analysis Compute nearest neighbour statistics to assess the level of clustering in a point vector layer Mean coordi nate s Compute either the normal or weighted mean center of an entire vector layer or multiple features based on a unique ID field Se Line intersections Locate intersections between lines and output results
177. ostgreSQL table or view definition to allow QGIS to load it QGIS requires that PostgreSQL layers contain a column that can be used as a unique key for the layer For tables this usually means that the table needs a primary key or a column with a unique constraint on it In QGIS this column needs to be of type int4 an integer of size 4 bytes Alternatively the ctid column can be used as primary key If a table lacks these items the oid column will be used instead Performance will be improved if the column is indexed note that primary keys are automatically indexed in PostgreSQL If the PostgreSQL layer is a view the same requirement exists but views don t have primary keys or columns with unique constraints on them In this case QGIS will try to find a column in the view that is derived from a suitable table column It does this by parsing the view definition SQL However there are several aspects of SQL that QGIS ignores these include the use of table aliases and columns that are generated by SQL functions If a suitable column cannot be found QGIS will not load the layer If this occurs the solution is to alter the view so that it does include a suitable column a type of int4 and either a primary key or with a unique constraint preferably indexed When dealing with views QGIS parses the view definition and 5 2 4 Importing Data into PostgreSQL shp2pgsql Data can be imported into PostgreSQL using a number of methods PostGI
178. ot in your path you need to provide the full path 6 Following the name of the external application add the URL used for doing a Google search up to but not included the search term http google com search q 7 The text in the Action field should now look like this firefox http google com search q 8 Click on the drop down box containing the field names for the lakes layer It s located just to the left of the Insert Field button 9 From the drop down box select NAMES Y and click Insert Field 10 Your action text now looks like this firefox http google com search q NAMES 11 Fo finalize the action click the button This completes the action and it is ready to use The final text of the action should look like this firefox http google com search gq NAMES We can now use the action Close the Layer Properties dialog and zoom in to an area of interest Make sure the lakes layer is active and identify a lake In the result box you ll now see that our action is visible QGIS 1 1 0 User Guide 45 5 WORKING WITH VECTOR DATA Figure 10 Select feature and choose action A Identify Results lakes 1 O X E Derived Area 2 637 194 219 301 sq AREA_KM2 2637 194219 NAMES lliamna Lake action Google Search cat 31 When we click on the action it brings up Firefox and navigates to the URL http www google com search q Tustumena It is also poss
179. other field names e g co11 and co110 you should in dicate so by surrounding the field name and the character with square brackets e g co110 This will prevent the co110 field name being mistaken for the co11 field name with a 0 on the end The brackets will be removed by QGIS when it substitutes in the value of the field If you want the substituted field to be surrounded by square brackets use a second set like this co110 The Identify Results dialog box includes a Derived item that contains information relevant to the layer type The values in this item can be accessed in a similar way to the other fields by using QGIS 1 1 0 User Guide 43 5 WORKING WITH VECTOR DATA preceeding the derived field name by Derived For example a point layer has an X and Y field and the value of these can be used in the action with Derived X and Derived Y The derived attributes are only available from the Identify Results dialog box not the Attribute Table dialog box Two example actions are shown below e konqueror http www google com search q nam e konqueror http www google com search q hh In the first example the web browser konqueror is invoked and passed a URL to open The URL per forms a Google search on the value of the nam field from our vector layer Note that the application or script called by the action must be in the path or you must provided the full p
180. points sequences of locations that make up a planned route and a tracklog or track of the receivers movement over time Waypoints routes and tracks are the three basic feature types in GPS data QGIS displays waypoints in point layers while routes and tracks are displayed in linestring layers 12 7 2 Loading GPS data from a file There are dozens of different file formats for storing GPS data The format that QGIS uses is called GPX GPS eXchange format which is a standard interchange format that can contain any number of waypoints routes and tracks in the same file To load a GPX file you first need to load the plugin Plugins gt Q Plugin Manager gt GPS Tools When this plugin is loaded a button with a small handheld GPS device will show up in the toolbar An example GPX file is available in the QGIS sample dataset qgis_sample_ data gps national_monuments gpx See Section 3 2 for more information about the sample data 1 Click on the GPS Tools icon and open the Load GPX file tab see figure 2 to the folder qgis_sample_data gps select the GPX file national_monuments gpx and click Use the browse button Jo select the GPX file then use the checkboxes to select the feature types you want to load from that GPX file Each feature type will be loaded in a separate layer when you click The file national_monuments gpx only includes waypoints 12 7 3 GPSBabel Since QGIS uses GPX f
181. process in a number of ways 4 3 1 Scale Dependent Rendering Scale dependent rendering allows you to specify the minimum and maximum scales at which a layer will be visible To set scale dependency rendering open the Properties dialog by double clicking on the layer in the legend On the tab set the minimum and maximum scale values and then click on the XJ Scale dependent visibility checkbox You can determine the scale values by first zooming to the level you want to use and noting the scale value in the QGIS status bar 4 3 2 Controlling Map Rendering Map rendering can be controlled in the following ways a Suspending Rendering To suspend rendering click the Render checkbox in the lower right corner of the statusbar When the Render box is not checked QGIS does not redraw the canvas in response to any of the events described in Section 4 3 Examples of when you might want to suspend rendering include Add many layers and symbolize them prior to drawing Add one or more large layers and set scale dependency before drawing Add one or more large layers and zoom to a specific view before drawing Any combination of the above Checking the Render box enables rendering and causes and immediate refresh of the map canvas b Setting Layer Add Option You can set an option to always load new layers without drawing them This means the layer will be added
182. ransparency tab 4 Click the Add values manually button A new row will appear in the pixel list 5 enter the raster value we use 0 here and adjust the transparency to 20 6 press the Apply button and have a look at the map You can repeat the steps 4 and 5 to adjust more values with custom transparency As you can see this is quite easy to set custom transparency but it can be quite a lot of work Therefor you can use the button Export to file to save your transparency list to a file The button Import from file loads your transparency settings and applies them to the current rasterlayer 6 3 3 Colormap The tab is only available when you have selected a single band rendering within the tab Symbology see chapt 6 3 1 Three ways of color interpolation are available e Discrete e Linear e Exact The button adds a color to the individual color table Double Clicking on the value column lets you inserting a specific value Double clicking on the color column opens the dialog Select color where you can select a color to apply on that value Alternativly you can click on the button Load colormap from Band Which tries to load the table from the band if it has any QGIS 1 1 0 User Guide 66 6 3 Raster Properties Dialog The block Generate new color map allows you to create newly categorized colormaps You only need to select the number
183. re 114 copyright 114 core 114 delimited text 114 diagram 114 145 DXF2Shape 114 ftools 114 georaster 114 gps 114 installing 110 Interpolation 114 manager 109 managing 109 MapServer Export 114 north arrow 114 OGR converter 114 Plugin Installer 114 145 146 Python Plugin Installer 110 quick print 114 scalebar 114 spit 114 145 types 109 upgrading 110 Zoom To Point 146 plugins settings 114 PostGIS 29 79 Exporting 36 layers 32 query builder 61 spatial index 37 GIST 37 SPIT 36 editing field names 36 importing data 35 loading 36 reserved words 36 PostgreSQL connection 32 33 testing 34 connection manager 33 connection parameters 33 database 33 host 33 layer details 34 loading layers 32 34 password 33 port 33 PostGIS 29 query builder 61 sslmode 33 username 33 Print composer tools 101 Projections coordinate reference system 72 QGIS 1 1 0 User Guide 177 Index CRS 72 custom 81 enabling 81 specifying 79 SRS 72 WMS 72 working with 79 projects 23 Query Builder 60 adding fields 60 changing layer definitions 60 generating sample list 60 getting all values 60 testing queries 60 query builder PostGIS 61 PostgreSQL 61 raster layer classify 67 raster layers 62 context menu 63 data formats 62 definition 62 GDAL implementation 62 georeferenced 62 histogram 68 loading 63 me
184. re 47 Dxf2Shape Converter Plugin A Dxf Importer x Input Dxf file qgis_sample_data gps geodata dxf e Output file qgis_sample_data gps geodata shp e Output file type O Polyline M Export text labels a Help Using the Plugin Polygon Point Q cancel lt 3 ok 1 Start QGIS load the Dxf2Shape plugin in the Plugin Manager see Section 11 1 1 and click on the Dxf2Shape Converter icon which appears in the QGIS toolbar menu The Dxf2Shape plugin dialog appears as shown in Figure 47 2 Enter input DXF file a name for the output Shapefile and the Shapefile type 3 Enable the 4 Click Ok Export text labels checkbox if you want to create an extra point layer with labels QGIS 1 1 0 User Guide 121 12 USING QGIS CORE PLUGINS 12 5 Georeferencer Plugin The Georeferencer Plugin is a tool for generating world files for rasters lt allows you to reference rasters to geographic or projected coordinate systems by creating a world file or by transforming the raster to a new coordinate system The basic approach to georeferencing a raster is to locate points on the raster for which you can accurately determine their coordinates The source of the coordinates can be 1 The raster itself sometimes coordinates are literally written on the raster In this case you can enter the coordinates manually 2 Other geore
185. re automatically loaded and enabled inside the QGIS Plugin Manager see Section 11 1 2 QGIS 1 1 0 User Guide 146 14 Help and Support 14 1 Mailinglists QGIS is under active development and as such it won t always work like you expect it to The preferred way to get help is by joining the qgis users mailing list qgis users Your questions will reach a broader audience and answers will benefit others You can subscribe to the qgis users mailing list by visiting the following URL http lists osgeo org mailman listinfo qgis user qgis developer If you are a developer facing problems of a more technical nature you may want to join the qgis developer mailing list here http lists osgeo org mailman listinfo qgis developer qgis commit Each time a commit is made to the QGIS code repository an email is posted to this list If you want to be up to date with every change to the current code base you can subscribe to this list at http lists osgeo org mailman listinfo qgis commit qgis trac This list provides email notification related to project management including bug reports tasks and feature requests You can subscribe to this list at http lists osgeo org mailman listinfo qgis trac qgis community team This list deals with topics like documentation context help user guide online experience including web sites blog mailing lists forums and translation efforts If you like to work on the user guide as well
186. reference system or you have to define a global layer or project wide CRS For PostGIS layers QGIS uses the spatial reference identifier that was specified when the layer was created For data supported by OGR QGIS relies on the presence of a format specific means of specifying the CRS In the case of shapefiles this means a file containing the Well Known Text WKT specification of the CRS The projection file has the same base name as the shapefile and a prj extension For example a shapefile named alaska shp would have a corresponding projection file named alaska prj 8 2 Specifying a Projection QGIS no longer sets the map CRS to the coordinate reference system of the first layer loaded When you start a QGIS session with layers that do not have a CRS you need to control and define the CRS definition for these layers This can be done globally or project wide in the tab under gt Gnome OSX or Settings gt Options KDE Windows See Figure 22 e X Prompt for CRS x Project wide default CRS will be used e x Global default CRS displayed below will be used QGIS 1 1 0 User Guide 79 8 WORKING WITH PROJECTIONS The global default CRS proj longlat ellps WGS84 datum WGS84 no_defs comes predefined in QGIS but can of course be changed and the new definition will be saved for subsequent QGIS sessions Figure 22 CRS tab in the QGIS Options Dialog A QGIS Options x Gen
187. represented in CSV format with the geometry data appearing in the OGC Well Known Text WKT format However in this version of QGIS text features from outside QGIS cannot be pasted to a layer within QGIS When would the copy and paste function come in handy Well it turns out that you can edit more than one layer at a time and copy paste features between layers Why would we want to do this Say we need to do some work on a new layer but only need one or two lakes not the 5 000 on our big_lakes layer We can create a new layer and use copy paste to plop the needed lakes into it As an example we are copying some lakes to a new layer 1 Load the layer you want to copy from source layer 2 Load or create the layer you want to copy to target layer 3 Start editing for target layer 4 Make the source layer active by clicking on it in the legend Select tool to select the feature s on the source layer QGIS 1 1 0 User Guide 56 5 5 Editing 6 Click on the Copy Features tool 7 Make the destination layer active by clicking on it in the legend 8 Click on the Paste Features tool 9 Stop editing and save the changes What happens if the source and target layers have different schemas field names and types are not the same QGIS populates what matches and ignores the rest If you don t care about the attributes being copied to the target layer it doesn t matter how you design the fiel
188. rlay not Vector subtraction v overlay xor Vector non intersection Table 31 GRASS Toolbox Vector update by other maps modules Vector update by other maps modules in the GRASS Toolbox Module name Purpose v rast stats Calculates univariate statistics from a GRASS raster map based on vector objects v what vect Uploads map for which to edit attribute table v what rast Uploads raster values at positions of vector points to the table v sample Sample a raster file at site locations Table 32 GRASS Toolbox Vector report and statistic modules Vector report and statistic modules in the GRASS Toolbox Module name Purpose v to db Put geometry variables in database v report Reports geometry statistics for vectors v univar Calculates univariate statistics on selected table column for a GRASS vector map v normal Tests for normality for points QGIS 1 1 0 User Guide 165 B GRASS TOOLBOX MODULES B 6 GRASS Toolbox imagery data modules This Section lists all graphical dialogs in the GRASS Toolbox to work with and analyse imagery data in a currently selected GRASS location and mapset Table 33 GRASS Toolbox Imagery analysis modules Imagery analysis modules in the GRASS Toolbox Module name Purpose i image mosaik Mosaic up to 4 images rgb his Red Green Blue RGB to Hue Intensity Saturation HIS raster map co
189. rogram at all For example if a patent license would not permit royalty free redistribution of the Program by all those who receive copies directly or indirectly through you then the only way you could satisfy both it and this License would be to refrain entirely from QGIS 1 1 0 User Guide 171 C GNU GENERAL PUBLIC LICENSE distribution of the Program If any portion of this section is held invalid or unenforceable under any particular circumstance the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims this section has the sole purpose of protecting the integrity of the free software distribution system which is implemented by public license practices Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system it is up to the author donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License 8 If the distribution and or use of the Program is restricted in certain countries either by patents or by copy righted interfaces the original copyrigh
190. roject 12 10 2 Creating the Map File The tool msexport to export a QGIS project file to a MapServer map file is installed in your QGIS binary directory and can be used independently of QGIS To use it from within QGIS you need to enable the MapServer Export Plugin first using the Plugin Manager see Section 11 1 1 Figure 57 Export to MapServer Dialog Map file Export to Mapserver x alaska map Save As QGIS project file alaska qgs i Browse C Export LAYER information only Map Name MyMap Width 600 Height 400 gt Units meters Image type png Web Interface Definition Template Browse Header Browse Footer Browse al Help Map file cancel lt 3 ok Enter the name for the map file to be created You can use the button at the right to browse for the directory where you want the map file created Qgis project file QGIS 1 1 0 User Guide 137 12 USING QGIS CORE PLUGINS Enter the full path to the QGIS project file qgs you want to export You can use the button at the right to browse for the QGIS project file Map Name A name for the map This name is prefixed to all images generated by the mapserver Map Width Width of the output image in pixels Map Height Height of the output image in pixels Map Units Units of measure used for output Image type
191. rors warnings will be displayed as each shapefile is processed Tip 12 IMPORTING SHAPEFILES CONTAINING POSTGRESQL RESERVED WORDS If a shapefile is added to the queue containing fields that are reserved words in the PostgreSQL database a dialog will popup showing the status of each field You can edit the field names prior to import and change any that are reserved words or change any other field names as desired Attempting to import a shapefile with reserved words as field names will likely fail ogr2ogr Beside shp2pgsq1 and SPIT there is another tool for feeding geodata in PostGIS ogr2ogr This is part of your GDAL installation To import a shapefile into PostGIS do the following ogr2ogr f PostgreSQL PG dbname postgis host myhost de user postgres password topsecret alaska shp This will import the shapefile alaska shp into the PostGIS database postgis using the user postgres with the password topsecret on host myhost de Note that OGR must be built with PostgreSQL to support PostGIS You can see this by typing ogrinfo formats grep i post QGIS 1 1 0 User Guide 36 5 2 PostGIS Layers If you like to use PostgreSQL s COPY command instead of the default INSERT INTO method you can export the following environment variable at least available on and X export PG_USE_COPY YES ogr2ogr does not create spatial indexes like shp2pgs1 does You need to create them manually us
192. rrent region v in db Import vector points from a database table containing coordinates v random Randomly generate a 2D 3D GRASS vector point map v kcv Randomly partition points into test train sets v outlier Romove outliers from vector point data v hull Create a convex hull v delaunay line Delaunay triangulation lines v delaunay area Delaunay triangulation areas v voronoi line Voronoi diagram lines v voronoi area Voronoi diagram areas QGIS 1 1 0 User Guide 164 B 5 GRASS Toolbox vector data modules Table 30 GRASS Toolbox Spatial vector and network analysis modules Spatial vector and network analysis modules in the GRASS Toolbox Module name Purpose v extract where Select features by attributes v extract list Extract selected features v select overlap Select features overlapped by features in another map v buffer Vector buffer v distance Find the nearest element in vector to for elements in vector from v net nodes Create nodes on network v net alloc Allocate network v net iso Cut network by cost isolines v net salesman Connect nodes by shortest route traveling salesman v net steiner Connect selected nodes by shortest tree Steiner tree v patch Create a new vector map by combining other vector maps v overlay or Vector union v overlay and Vector intersection v ove
193. rtex and segment as default snap mode You can also define a default snapping tolerance and a search radius for vertex edits The tolerance an be set either in map units or in pixels In our digitizing project working with the Alaska dataset the units are in feet Your results may vary but something on the order of 300ft should be fine at a scale of 1 10 000 should be a reasonable setting 2 A layer based snapping tolerance can be defined by choosing Settings or File gt gt Project Properties In the tab section Digitize you can click on Snapping options to enable and adjust snapping mode and tolerance on a layer basis see Figure 13 Figure 13 Edit snapping options on a layer basis amp we E Snapping options x Layer Mode Tolerance Units airports to vertex po jo map units grassl fto vertex Jo map units j s alaska lo vertex s o map units builtups to vertex m 0 map units x Cancel QGIS 1 1 0 User Guide 50 5 5 Editing Search radius Search radius is the distance QGIS uses to search for the closest vertex you are trying to move when you click on the map If you aren t within the search radius QGIS won t find and select any vertex for editing and it will pop up an annoying warning to that effect Snap tolerance and search radius are set in map units or pixels so you may find you need to experiment to get them set right
194. s sampling geoprocessing ge ometry and database management tools You can also use the integrated GRASS tools which include the complete GRASS functionality of more than 300 modules See Section 9 Publish maps on the internet QGIS can be used to export data to a mapfile and to publish them on the internet using a webserver with UMN MapServer installed QGIS can also be used as a WMS or WFS client and as WMS server Extend QGIS functionality through plugins QGIS can be adapted to your special needs with the extensible plugin architecture QGIS provides libraries that can be used to create plugins You can even create new applications with C or Python e Core Plugins Add WFS Layer Add Delimited Text Layer Coordinate Capture Decorations Copyright Label North Arrow and Scale bar Diagram Overlay Dxf2Shp Converter Georeferencer fTools GPS Tools GRASS integration Interpolation Plugin OGR Layer Converter Quick Print SPIT Shapefile to PostgreSQL PostGIS Import Tool Mapserver Export Python Console Python Plugin Installer e Python Plugins QGIS offers a growing number of external python plugins that are provided by the com munity These plugins reside in the the official PyQGIS repository and can be easily installed using the python plugin installer See Section 11 QGIS 1 1 0 User Guide 3 1 FOREWORD 1 2 Conventions This section describes a collection of uniform styles throughout the manual Th
195. s feature is enabled all repositories listed and enabled in the tab are checked for updates each time the program is started The frequency of update checking QGIS 1 1 0 User Guide 112 11 2 Data Providers can be adjusted using the dropdown menu and may be adjusted from once a day right up to once a month If a new plugin or update is available for one of the installed plugins a notification will appear in the Status Bar If the checkbox is disabled looking for updates and news is performed only when the Plugin Installer is manually launched from the menu Some internet connections will cause problems when attempting to automatically check for updates In these cases a Looking for new plugins indicator will remain visible in the Status Bar during your entire QGIS session and may cause a program crash when exiting In this case please disable the checkbox In addition you may specify the type of plugins that are displayed by the Plugin Installer Under Allowed plugins you can specify whether you would like to e Only show plugins from the official repository e Show all plugins except those marked as experimental e or Show all plugins even those marked as experimental Tip 42 USING EXPERIMENTAL PLUGINS Experimental plugins are generally unsuitable for production use These plugins are in the early stages of development and should be considered incomplete or proof of concept tools The QGIS development t
196. s is e g used for area boundaries because the category values are connected via the centroid e Category A number ID is attached to each digitized geometry element lt is used to connect each geometry element with its attributes e Field layer Each geometry element can be connected with several attribute tables using different GRASS geometry layers Default layer number is 1 Tip 38 CREATING AN ADDITIONAL GRASS LAYER WITH QGIS If you would like to add more layers to your dataset just add a new number in the Field layer entry box and press return In the Table tab you can create your new table connected to your new layer QGIS 1 1 0 User Guide 93 9 GRASS GIS INTEGRATION Figure 28 GRASS Digitizing Category Tab amp E So E i eU AvE Settings Symbology Table Mode Nest not used Ss Category 77 Layer 1 H Settings Tab The Settings tab allows you to set the snapping in screen pixels The threshold defines at what distance new points or line ends are snapped to existing nodes This helps to prevent gaps or dangles between boundaries The default is set to 10 pixels Figure 29 GRASS Digitizing Settings Tab 4 i Edit OA O A E o Category Settings Symbology Table Snapping in screen pixels ad es Symbology Tab The Symbology tab allows you to view and set symbology and color settings for various geometry types an
197. s of certain wavelengths of light As you can imagine a large raster takes up more file space A raster with smaller cells can provide more detail but takes up more file space The trick is finding the right balance between cell size for storage purposes and cell size for analytical or mapping purposes 2 1 2 Vector Data Vector data is also used in geospatial applications If you stayed awake during trigonometry and coordinate geometry classes you will already be familiar with some of the qualities of vector data In its simplest sense vectors are a way of describing a location by using a set of coordinates Each coordinate refers to a geographic location using a system of x and y values This can be thought of in reference to a Cartesian plane you know the diagrams from school QGIS 1 1 0 User Guide 7 2 INTRODUCTION TO GIS that showed an x and y axis You might have used them to chart declining retirement savings or increasing compound mortgage interest but the concepts are essential to geospatial data analysis and mapping There are various ways of representing these geographic coordinates depending on your purpose This is a whole area of study for another day map projections Vector data takes on three forms each progressively more complex and building on the former 1 Points A single coordinate x y represents a discrete geographic location 2 Lines Multiple coordinates x1 y1 x2 y2 x3 y4 xn yn strung t
198. se X you can find your settings in HOME Library Preferences org qgis qgis plist fj E settings are stored in the registry under HKEY CURRENT USER Software QuantumGIS qgis 4 8 Spatial Bookmarks Spatial Bookmarks allow you to bookmark a geographic location and return to it later 4 8 1 Creating a Bookmark To create a bookmark 1 Zoom or pan to the area of interest 2 Select the menu option View gt New Bookmark or press Ctrl B 3 Enter a descriptive name for the bookmark up to 255 characters 4 Click to add the bookmark or to exit without adding the bookmark Note that you can have multiple bookmarks with the same name 4 8 2 Working with Bookmarks To use or manage bookmarks select the menu option View gt Show Bookmarks The Geospatial Bookmarks dialog allows you to zoom to or delete a bookmark You can not edit the bookmark name or coordinates 4 8 3 Zooming to a Bookmark From the Geospatial Bookmarks dialog select the desired bookmark by clicking on it then click You can also zoom to a bookmark by double clicking on it QGIS 1 1 0 User Guide 27 4 FEATURES AT A GLANCE 4 8 4 Deleting a Bookmark To delete a bookmark from the Geospatial Bookmarks dialog click on it then click Confirm your choice by clicking or cancel the delete by clicking QGIS 1 1 0 User Guide 28 5 Working with Vector Dat
199. see Section 5 5 4 Tip 36 CREATING AN ATTRIBUTE TABLE FOR A NEW GRASS VECTOR LAYER If you want to assign attributes to your digitized geometry features make sure to create an attribute table with columns before you start digitizing see Figure 31 9 7 Digitizing and editing a GRASS vector layer The digitizing tools for GRASS vector layers are accessed using the Edit GRASS vector layer icon on the toolbar Make sure you have loaded a GRASS vector and it is the selected layer in the legend before clicking on the edit tool Figure 28 shows the GRASS edit dialog that is displayed when you click on the edit tool The tools and settings are discussed in the following sections Tip 37 DIGITIZING POLYGONES IN GRASS If you want to create a polygone in GRASS you first digitize the boundary of the polygone setting the mode to No category Then you add a centroid label point into the closed boundary setting the mode to Next not used The reason is that a topological vector model links attribute information of a polygon always to the centroid and not to the boundary Toolbar In Figure 27 you see the GRASS digitizing toolbar icons provided by the GRASS plugin Table 3 explains the available functionalities Figure 27 GRASS Digitizing Toolbar amp UN e RAG AY ED Category Tab The Category tab allows you to define the way in which the category values will be assigned to a new geometry element e Mode wh
200. sion to link the code of this program with the Qt library including but not limited to the following versions both free and commercial Qt Non commerical Windows Qt Windows Qt X11 Qt Mac and Qt Embedded or with modified versions of Qt that use the same license as Qt and distribute linked combinations including the two You must obey the GNU General Public License in all respects for all of the code used other than Qt If you modify this file you may extend this exception to your version of the file but you are not obligated to do so If you do not wish to do so delete this exception statement from your version QGIS 1 1 0 User Guide 174 Literature 1 T Mitchell Web mapping illustrated published by o reilly 2005 2 M Neteler and H Mitasova Open source gis A grass gis approach 3 edition springer new york 2008 Web References 3 GDAL Software Suite http www gdal org 2009 4 GRASS GIS http grass osgeo org 2009 5 OGR Software Suite http www gdal org ogr 2009 6 PostGIS http postgis refractions net 2009 7 Web Map Service 1 1 1 Implementation Specification http portal opengeospatial org 2002 8 Web Map Service 1 3 0 Implementation Specification http portal opengeospatial org 2004 Index W 43 actions 43 defining 43 examples 44 using 44 Allow Editing 52 Analysis tools 131 attributes 46 bookmarks 27 command line options 12 coordinate re
201. software generally NO WARRANTY 11 BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE THERE IS NO WARRANTY FOR THE PROGRAM TO THE EXTENT PERMITTED BY APPLICABLE LAW EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND OR OTHER PARTIES PROVIDE THE PROGRAM AS IS WITHOUT WARRANTY OF ANY KIND EITHER EXPRESSED OR IMPLIED INCLUDING BUT NOT LIM ITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PUR POSE THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU SHOULD THE PROGRAM PROVE DEFECTIVE YOU ASSUME THE COST OF ALL NECESSARY SERVIC ING REPAIR OR CORRECTION 12 INNO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER OR ANY OTHER PARTY WHO MAY MODIFY AND OR REDISTRIBUTE THE PRO QGIS 1 1 0 User Guide 172 GRAM AS PERMITTED ABOVE BE LIABLE TO YOU FOR DAMAGES INCLUDING ANY GENERAL SPE CIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED IN ACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES QGIS 1 1 0 User Guide 173 C GNU GENERAL PUBLIC LICENSE C 1 Quantum GIS Qt exception for GPL In addition as a special exception the QGIS Development Team gives permis
202. ss area greater Reclasses a raster map greater than user specified area size in hectares r reclass area lesser Reclasses a raster map less than user specified area size in hectares r reclass Reclass a raster using a reclassification rules file r recode Recode raster maps r rescale Rescales the range of category values in a raster map layer QGIS 1 1 0 User Guide 161 B GRASS TOOLBOX MODULES Table 24 GRASS Toolbox Hydrologic modelling modules Hydrologic modelling modules in the GRASS Toolbox Module name Purpose r carve Takes vector stream data transforms it to raster and subtracts depth from the output DEM r fill dir Filters and generates a depressionless elevation map and a flow direc tion map from a given elevation layer r lake xy Fills lake from seed point at given level r lake seed Fills lake from seed at given level r topidx Creates a 3D volume map based on 2D elevation and value raster maps r basins fill Generates a raster map layer showing watershed subbasins r water outlet Watershed basin creation program Table 25 GRASS Toolbox Reports and statistic analysis modules Reports and statistic analysis modules in the GRASS Toolbox Module name Purpose r category Prints category values and labels associated with user specified raster map layers r sum Sums up the raster cell values r report Reports stat
203. stscript of PDF e The tab displays the properties for the selected map element Click the Select Move item icon to select an element e g legend scalebar or label on the canvas Then click the Item tab and customize the settings for the selected element You can add multiple elements to the composer It is also possible to have more than one map view or legend or scalebar in the print composer canvas Each element has its own properties and in the case of the map its own extent 10 1 1 Adding a current QGIS map canvas to the Print Composer To add the QGIS map canvas click on the Add new map from QGIS map canvas button in the print composer toolbar and drag a rectangle on the composer canvas with the left mouse button to add the map You will see an empty box with a Map will be printed here message To display the current map you can choose between three different modes in the map tab e Preview Rectangle Y is the default setting It only displays an empty box with a message Map will be printed here e Preview Cache Y renders the map in the current screen resolution If case you zoom in or out the composer window the map is not rendered again but the image will be scaled e Preview Render Y means that if you zoom in or out the composer window the map will be rendered again but for space reasons only up to a maximum resolu
204. symbolizing them cus tomizing the colors and then creating a map file for MapServer 12 10 1 Creating the Project File The MapServer Export Plugin operates on a saved QGIS project file and not on the current contents of the map canvas and legend This has been a source of confusion for a number of users As described below before you start using the MapServer Export Plugin you need to arrange the raster and vector layers you want to use in MapServer and save this status in a QGIS project file Figure 56 Arrange raster and vector layers for QGIS project file A Quantum GIS 1 1 0 Pan Unstable alaska ele File Edit View Layer Plugins Tools Help Layers E Overview am MS 2732789 5372173 Scale 1 33972301 Y M Render fig In this example we demonstrate the four steps required to create a simple project file which can be used to create the MapServer map file We use raster and vector files from the QGIS sample dataset 3 2 1 Add the raster layer Landcover tif clicking on the Add Raster Layer icon QGIS 1 1 0 User Guide 136 12 10 MapServer Export Plugin 2 Add the vector Shapefiles lakes shp majrivers shp and airports shp from the QGIS sam ple dataset clicking on the Add Vector Layer icon 3 Change the colors and symbolize the data as you like For example see Figure 4 Save a new project named mapserverproject qgs using gt l Save P
205. t Label Plugin The title of this plugin is a bit misleading you can add any random text to the map Figure 44 Copyright Label Plugin amp Copyright Label Plugin x Enter your copyright label below This plugin supports basic html markup tags for formatting the label For exa ole lt B gt Bold text lt B gt lt l gt Italics lt I gt note amp copy gives a copyright symbol amp copy QGIS 2009 Placement Bottom Right color MN y Enable Copyright Label Erer J on 1 Make sure the plugin is loaded 2 Click on gt gt Copyright Label or use the Copyright Label button from the Toolbar 3 Enter the text you want to place on the map You can use HTML as shown in the example 4 Choose the placement of the label from the Placement Bottom Right Y drop down box 5 Make sure the Enable Copyright Label checkbox is checked 6 Click OK In the example above default places a copyright symbol followed by the date in the lower right hand corner of the map canvas QGIS 1 1 0 User Guide 118 123 Decorations Plugins 12 3 2 North Arrow Plugin The North Arrow plugin places a simple north arrow on the map canvas At present there is only one style available You can adjust the angle of the arrow or let QGIS set the direction automatically If you choose to let QGIS determine the direction it makes its best guess as to how
206. t arrow key to pan East left arrow key to pan West up arrow key to pan North and down arrow key to pan South You can also pan the map using the space bar just move the mouse while holding down space bar 4 2 5 Map Overview The map overview area provides a full extent view of layers added to it Within the view is a rectangle showing the current map extent This allows you to quickly determine which area of the map you are currently viewing Note that labels are not rendered to the map overview even if the layers in the map QGIS 1 1 0 User Guide 19 4 FEATURES AT A GLANCE overview have been set up for labeling You can add a single layer to the overview by right clicking on it in the legend and select X Show in overview You can also add layers to or remove all layers from the overview using the Overview tools on the toolbar If you click and drag the red rectangle in the overview that shows your current extent the main map view will update accordingly 4 2 6 Status Bar The status bar shows you your current position in map coordinates e g meters or decimal degrees as the mouse pointer is moved across the map view To the left of the coordinate display in the status bar is a small button that will toggle between showing coordinate position or the view extents of the map view as you pan and zoom in and out A progress bar in the status bar shows progress of rendering as each layer is drawn to the map view
207. t bin Exports a GRASS raster to a binary ar 4 a Modules Tree b Searchable Modules List grouped Modules Tree or the searchable Modules List tab Clicking on a grapical module icon a new tab will be added to the toolbox dialog providing three new sub tabs Options Output and In Figure 33 you see an example for the GRASS module v buffer Figure 33 GRASS Toolbox Module Dialogs amp GRASS Nols alaskcaye GRASS Wolk alasicayc Modules Tree Modules List Browser Modules Tree Modules List Browser GRASS T Eae Modules Tree Modules List Browser Module v buffer Module v buffer Options Output Manual v buffer input rivers demo type line layer 1 buffer 200 output rivers200 Module v buffer Options Output Manual Options Output Manual m Name der Vektoreingabekarte rivers rivers demo 1 line IM m Pufferdistanz in Karteneinheiten Toleranz in Kartonainiaton 2 i v buffer Creates a buffer around features 200 of given type areas must contain centroid KEYWORDS C INE ANN lt p INERCIA RAD m Name der Vektorausgabekarte Stop View output Close a Module Options b Modules Output c Module Manual Run view output Close l Stop view output Close
208. t each intersection of vector map v clean snap Cleaning topology snap lines to vertex in threshold v clean rmdangles Cleaning topology remove dangles v clean chdangles Cleaning topology change the type of boundary dangle to line v clean rmbridge Remove bridges connecting area and island or 2 islands v clean chbridge Change the type of bridges connecting area and island or 2 islands v clean rmdupl Remove duplicate lines pay attention to categories v clean rmdac Remove duplicate area centroids v clean bpol Break polygons Boundaries are broken on each point shared between 2 and more polygons where angles of segments are different v clean prune Remove vertices in threshold from lines and boundaries v clean rmarea Remove small areas removes longest boundary with adjacent area v clean rmline Remove all lines or boundaries of zero length v clean rmsa Remove small angles between lines at nodes v type lb Convert lines to boundaries v type bl Convert boundaries to lines v type pc Convert points to centroids v type cp Convert centroids to points v centroids Add missing centroids to closed boundaries v build polylines Build polylines from lines v segment Creates points segments from input vector lines and positions v to points Create points along input lines v parallel Create parallel line to input lines v disso
209. t holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries so that distribution is permitted only in or among countries not thus excluded In such case this License incorporates the limitation as if written in the body of this License 9 The Free Software Foundation may publish revised and or new versions of the General Public License from time to time Such new versions will be similar in spirit to the present version but may differ in detail to address new problems or concerns Each version is given a distinguishing version number If the Program specifies a version number of this License which applies to it and any later version you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation If the Program does not specify a version number of this License you may choose any version ever published by the Free Software Foundation 10 If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different write to the author to ask for permission For software which is copyrighted by the Free Software Foundation write to the Free Software Foundation we sometimes make exceptions for this Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of
210. tadata 67 metadata 68 properties 67 pyramids 67 resolution pyramids 67 standard deviation 65 statistics 68 supported channels 64 supported formats 151 transparency 65 rasters metadata 74 properties 74 WMS 69 rendering 20 options 21 quality 22 scale dependent 21 suspending 21 update during drawing 22 Research tools 132 scale 21 calculate 20 security 34 settings 34 shapefile format 29 loading 29 specification 29 shapefiles 29 SHP files 29 spatial bookmarks seebookmarks27 spatial index shapefiles 30 SpatiaLite layers 38 SpatiaLite layers properties dialog 38 SRS 72 symbology changing 40 TAB files 29 Toggle Editing 52 toolbars 17 vector layers 29 61 add island 56 ring 56 adding feature 53 vertex 55 Arcinfo Binary Coverage 31 QGIS 1 1 0 User Guide 178 Index copy feature 56 cut feature 56 deleting feature 57 vertex 55 diagram 47 editing 51 vertex 55 ESRI shapefiles 29 MapInfo 31 move feature 54 moving vertex 55 paste feature 56 PostGIS see PostGIS properties dialog 38 renderers continuous color 40 graduated symbol 40 single symbol 39 unique value 40 SpatlaLlte see SpatiaLite split feature 54 styles 40 symbology 39 transparency 41 WFS authenticate remote server 78 remote server 77 secured WFS server 78 WKT 79 WMS authentification 70 capabilites 74 client 69 about 69 connection
211. tasets include remote sensing data such as aerial photography or satellite imagery and modelled data such as an elevation matrix Unlike vector data raster data typically do not have an associated database record for each cell They are geocoded by its pixel resolution and the x y coordinate of a corner pixel of the raster layer This allows QGIS to position the data correctly in the map canvas QGIS makes use of georeference information inside the raster layer e g GeoTiff or in an appropriate world file to properly display the data 6 2 Loading raster data in QGIS Raster layers are loaded either by clicking on the Load Raster icon or by selecting the View Ps Add Raster Layer menu option More than one layer can be loaded at the same QGIS 1 1 0 User Guide 62 6 3 Raster Properties Dialog time by holding down the or key and clicking on multiple items in the dialog Open a GDAL Supported Raster Data Source Once a raster layer is loaded in the map legend you can click on the layer name with the right mouse button to select and activate layer specific features or to open a dialog to set raster properties for the layer Right mouse button menu for raster layers e Zoom to layer extent e Zoom to best scale 100 e Show in overview e Remove e Properties e Rename Add Group e Expand all e Collapse all lib e Show file groups 6 3 Raster Properties
212. th the QGIS source code 3 2 Sample Data The user guide contains examples based on the QGIS sample dataset gy The Windows installer has an option to download the QGIS sample dataset If checked the data will be downloaded to your My Documents folder and placed in a folder called GIS Database You may use Windows Explorer to move this folder to any convenient location If you did not select the checkbox to install the sample dataset during the initial QGIS installation you can either e use GIS data that you already have e download the sample data from the QGIS website http qgis osgeo org download or e uninstall QGIS and reinstall with the data download option checked X For GNU Linux and Mac OSX there are not yet dataset installation packages available as rpm deb or dmg To use the sample dataset download the file qgis_sample_data as ZIP or TAR archive from http download osgeo org qgis data and unzip or untar the archive on your system The Alaska dataset includes all GIS data that are used as examples and screenshots in the user guide and also includes a small GRASS database The projection for the QGIS sample dataset is Alaska Albers Equal Area with unit feet The EPSG code is 2964 PROJCS Albers Equal Area GEOGCS NAD27 QGIS 1 1 0 User Guide 9 3 GETTING STARTED DATUM North_American_Datum_1927 SPHEROID Clarke 1866 6378206 4 294 978698213898 AUTHORITY EPSG 7008 TOWGS84 3 142 183 0 0 0 0
213. the Add Layer s from a Server dialog Figure 20 Dialog for searching WMS servers after some keywords A Add Layer s from a Server lt keto gt Servers Server Search geology Title URL Desen 2 f 4 Geological indicators of flooding http oge bgs ac uk c Geological maps show BGS 625K Geology http www gis bgs ac Use of this web servic _ la BGS Bedrock and Superficial geology http ogc bgs ac uk c e Add selected row to WMS list Image encoding e JPEG PNG TIFF r Coordinate Reference System WGS 84 Change Help Ac Close Response is complete As you can see it is possible to enter a search string in the textfield an hit the button After a short while the search result will be populated into the tab below the textfield Browse the result list and inspect your searchresults within the table To visualize the results select an table entry press the Add selected row to WMS list button and change back to the tab QGIS automatically has updated your server list and the selected searchresult is already enabled in the list of saved WMS servers You only need to request the list of layers by clicking the button QGIS 1 1 0 User Guide 73 7 WORKING WITH OGC DATA This option is quite handy when you want to search maps by specific keywords Basically this option is a frontend to the API of http geopole org 7
214. the ERDAS Img file landcover img and click 3 If the file is not listed check if the Filetype combobox at the bottom of the dialog is set on the right type in this case Erdas Imagine Images img IMG 4 Now click on the Load Vector icon 5 In the new Add Vector Layer dialog click 6 Browse to the folder ggis_sample_data gm1 select GML from the filetype combobox then select the GML file lakes gm1 and click then in Add Vector dialog click OK 7 Zoom in a bit to your favorite area with some lakes 8 Double click the lakes layer in the map legend to open the Layer Properties dialog 9 Click on the Symbology tab and select a blue as fill color 10 Click on the tab and check the Display labels checkbox to enable labeling Choose NAMES field as Field containing label 11 Click Apply Figure 1 A Simple QGIS Session You can see how easy it is to visualize raster and vector layers in QGIS Let s move on to the sections that follow to learn more about the available functionality features and settings and how to use them QGIS 1 1 0 User Guide 11 4 FEATURES AT A GLANCE 4 Features at a Glance After a first and simple sample session in Section 3 we now want to give you a more detailed overview of the features of QGIS Most features presented in the following chapters will be explained and described in own sections later in the manual 4 1
215. this is actually the download command for the predefined device type GPS device Garmin serial Y and then use it to download waypoints from port dev ttySo to the file output gpx QGIS will replace the keywords and run the command gpsbabel w i garmin o gpx dev ttySO output gpx The upload command is the command that is used to upload data to the device The same keywords are used but in is now replaced by the name of the GPX file for the layer that is being uploaded and out is replaced by the port name You can learn more about GPSBabel and it s available command line options at http www gpsbabel org Once you have created a new device type it will appear in the device lists for the download and upload tools QGIS 1 1 0 User Guide 130 12 8 fTools Plugin 12 8 fTools Plugin The goal of the fTools python plugin is to provide a one stop resource for many common vector based GIS tasks without the need for additional software libraries or complex workarounds It provides a growing suite of spatial data management and analysis functions that are both fast and functional fTools is now automatically installed and enabled in new versions of QGIS and as with all plugins it can be disabled and enabled using the Plugin Manager See Section 11 1 When enabled the fTools plugin adds a menu to QGIS providing functions ranging from Analysis and Research Tools to Geometry and Ge
216. this list is a good starting point to ask your questions You can subscribe to this list at http lists osgeo org mailman listinfo qgis community team qgis release team This list deals with topics like the release process packaging binaries for various OS and announcing new releases to the world at large You can subscribe to this list at http lists osgeo org mailman listinfo qgis release team QGIS 1 1 0 User Guide 147 14 HELP AND SUPPORT qgis psc This list is used to discuss Steering Committee issues related to overall management and direction of Quantum GIS You can subscribe to this list at http lists osgeo org mailman listinfo qgis psc You are welcome to subscribe to any of the lists Please remember to contribute to the list by answer ing questions and sharing your experiences Note that the qgis commit and qgis trac are designed for notification only and not meant for user postings 14 2 IRC We also maintain a presence on IRC visit us by joining the qgis channel on irc freenode net Please wait around for a response to your question as many folks on the channel are doing other things and it may take a while for them to notice your question Commercial support for QGIS is also available Check the website http agis org content view 90 91 for more information If you missed a discussion on IRC not a problem We log all discussion so you can easily catch up Just go to http logs qgis org and read the IRC lo
217. tion You can resize the map later by clicking on the Select Move item button selecting the el ement and dragging one of the blue handles in the corner of the map With the map selected you can now adapt more properties in the map tab Resize the map item specifying the width and height or the scale Define the map extend using Y and X min max values or clicking the set to map canvas extend button Update the map preview and select whether to see a preview from cache or an empty rectangle with a Map will be printed here message Define colors and outline width for the element frame set a background color and opacity for the map canvas And you can also select or unselect to display an element frame with the frame checkbox see Figure 36 If you change the view on the QGIS map canvas by zooming or panning or changing vector or raster QGIS 1 1 0 User Guide 103 10 PRINT COMPOSER Figure 36 Print Composer map item tab content A General ltem Map width 83 Height 62 3942 Scale 1 4611966578239 Map extent min 2260028 875 X max 700 875 Y min 46687 509 Y max 789 572 set Lo map canvas extent a Width height and extend dialog Preview Cache E Update preview Composer item properties Color Frame Background Opacity a 3 Outline width 3 30 Position x Frame b Properties dialog properties you can update the print composer v
218. tively explore spatial data with a friendly GUI The many helpful tools available in the GUI include on the fly projection map composer overview panel spatial bookmarks identify select features edit view search attributes feature labeling change vector and raster symbology add a graticule layer now via fTools plugin decorate your map with a north arrow scale bar and copyright label save and restore projects Create edit manage and export data You can create edit manage and export vector maps in several formats Raster data have to be imported into GRASS to be able to edit and export them into other formats QGIS offers the following digitizing tools for OGR supported formats and GRASS vector layer create and edit shapefiles and GRASS vector layers geocode images with the Georeferencer plugin GPS tools to import and export GPX format and convert other GPS formats to GPX or down upload directly to a GPS unit on Linux usb has been added to list of GPS devices create PostGIS layers from shapefiles with the SPIT plugin improved handling of PostGIS tables manage vector attribute tables with the new Attribute table see Section 5 5 5 or Table Manager plugin save screenshots as georeferenced images QGIS 1 1 0 User Guide 2 1 1 Features Analyse data You can perform spatial data analysis on PostgreSQL PostGIS and other OGR supported formats using the fTools python plugin QGIS currently offers vector analysi
219. tructions in Windows visit the module home page If you are using a proxy you may need to configure it under gt Gnome OSX or Settings gt Options KDE Windows on the tab The Uninstall plugin button is enabled only if the selected plugin is installed and is not a core plugin Note that if you have installed an update to a core plugin you can uninstall this update with the Uninstall plugin and revert to the version shipped with Quantum GIS This default version however cannot be uninstalled Repositories tab The second tab Repositories contains a list of plugin repositories available for the Plugin Installer By default only the QGIS Official Repository is enabled You can add several user contributed repositories including the central QGIS Contributed Repository and other external repos itories by clicking the Add 3rd party repositories button The added repositories contain a large number of useful plugins which are not maintained by the QGIS Development Team As such we cannot take any responsibility for them You can also manage the repository list manually that is add remove and edit the entries Temporarily disabling a particular repository is possible by clicking the button Options tab The tab is where you can configure the settings of the Plugin Installer The Check for updates on startup checkbox tells QGIS to automatically look for plugin updates and news By default if thi
220. ution and only if you received the program in object code or executable form with such an offer in accord with Subsection b above The source code for a work means the preferred form of the work for making modifications to it For an exe cutable work complete source code means all the source code for all modules it contains plus any associated interface definition files plus the scripts used to control compilation and installation of the executable However as a special exception the source code distributed need not include anything that is normally distributed in either source or binary form with the major components compiler kernel and so on of the operating system on which the executable runs unless that component itself accompanies the executable If distribution of executable or object code is made by offering access to copy from a designated place then offering equivalent access to copy the source code from the same place counts as distribution of the source code even though third parties are not compelled to copy the source along with the object code 4 You may not copy modify sublicense or distribute the Program except as expressly provided under this License Any attempt otherwise to copy modify sublicense or distribute the Program is void and will automat ically terminate your rights under this License However parties who have received copies or rights from you under this License will not have their licenses terminate
221. version of QGIS the transparency setting is hard coded to be always on where available Tip 28 WMS LAYER TRANSPARENCY The availability of WMS image transparency depends on the image encoding used PNG and GIF support transparency whilst JPEG leaves it unsupported Coordinate Reference System A Coordinate Reference System CRS is the OGC terminology for a QGIS Projection Each WMS Layer can be presented in multiple CRSs depending on the capability of the WMS server You may notice that the x changes in the Coordinate Reference System x available header as you select and deselect layers from the section To choose a CRS select and a screen similar to Figure 23 in Section 8 3 will appear The main difference with the WMS version of the screen is that only those CRSs supported by the WMS Server will be shown QGIS 1 1 0 User Guide 72 7 2 WMS Client Tip 29 WMS PROJECTIONS For best results make the WMS layer the first layer you add to your project This allows the project projection to inherit the CRS you used to render the WMS layer On the fly projection see Section 8 2 can then be used to fit any subsequent vector layers to the project projection In this version of QGIS if you add a WMS layer later and give it a different CRS to the current project projection unpredictable results can occur 7 2 4 Server Search Within QGIS 1 1 X you can search for WMS servers Figure 20 shows the newly created tab with
222. w resolution r resamp rst Reinterpolates and computes topographic analysis using regularized spline with tension and smoothing r support Allows creation and or modification of raster map layer support files r support stats Update raster map statistics r proj Re project a raster map from one location to the current location Table 20 GRASS Toolbox Raster color management modules Raster color management modules in the GRASS Toolbox Module name Purpose r colors table Set raster color table from setted tables r colors rules Set raster color table from setted rules r colors rast Set raster color table from existing raster r blend Blend color components for two raster maps by given ratio r composite Blend red green raster layers to obtain one color raster r his Generates red green and blue raster map layers combining hue in tensity and saturation his values from user specified input raster map layers QGIS 1 1 0 User Guide 159 B GRASS TOOLBOX MODULES Table 21 GRASS Toolbox Spatial raster analysis modules Spatial raster analysis modules in the GRASS Toolbox Module name Purpose r buffer Raster buffer r mask Create a MASK for limiting raster operation r mapcalc Raster map calculator r mapcalculator Simple map algebra r neighbors Raster neighbors analyses v neighbors Count of neighbouri
223. y name alaska Display field cat proj longlat ellps WGS84 datum WGS84 no_defs Create Spatial Index Change CRS l rO Use scale dependent rendering Minimum 1 Maximum Subset Query Builder Restore Default Style Save As Default Load Style Save Style el E 7 f a EN 5 4 1 General Tab The tab is essentially like that of the raster dialog lt allows you to change the display name set scale dependent rendering options create a spatial index of the vector file only for OGR supported formats and PostGIS and view or change the projection of the specific vetor layer The Query Builder button allows you to create a subset of the features in the layer but this but ton currently only is available when you open the attribute table and select the ah button next to Advanced search 5 4 2 Symbology Tab QGIS supports a number of symbology renderers to control how vector features are displayed Cur rently the following renderers are available Single symbol a single style is applied to every object in the layer Graduated symbol objects within the layer are displayed with different symbols classified by the QGIS 1 1 0 User Guide 39 5 WORKING WITH VECTOR DATA values of a particular field Continuous color objects within the layer are displayed with a spread of colours classified by the numerical values within a sp
224. ysis modules in the GRASS Toolbox Module name Purpose db connect Sets general DB connection mapset db connect schema Sets general DB connection mapset with a schema v db reconnect all Reconnect vector to a new database db login Set user password for driver database db in ogr Imports attribute tables in various formats v db addtable Create and add a new table to a vector v db addcol Adds one or more columns to the attribute table connected to a given vector map v db dropcol Drops a column from the attribute table connected to a given vector map v db renamecol Renames a column in a attribute table connected to a given vector map v db update_const Allows to assign a new constant value to a column v db update_query Allows to assign a new constant value to a column only if the result of a query is TRUE v db update_op Allows to assign a new value result of operation on column s to a column in the attribute table connected to a given map v db update_op_query Allows to assign a new value to a column result of operation on col umn s only if the result of a query is TRUE db execute Execute any SQL statement db select Prints results of selection from database based on SQL v db select Prints vector map attributes v db select where Prints vector map attributes with SQL v db join Allows to join a table to a vector map table v db univ

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