Home
Quantum GIS User Guide - OSGeo Server
Contents
1. 9 2 7 Defining new device types There are lots of different types of GPS devices The QGIS developers can t test all of them so if you have one that does not work with any of the device types listed in the download and upload 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 window To define a new device you simply click the New device button enter a name a download command and an upload command for your device and click the Update device button The name 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 in and out when it runs the command if you are downloading routes and type will be replaced by w if you are downloading waypoints r 4 if you are downloading tracks These are command line options that tell GPSBabel which feature type to download 45 QGIS User Guide Version 0 7 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
2. Description Select the file containing delimited text with lat lon coordinates that you would like to use as a point layer and this plugin will do the job for you Use the layer name box to specify the legend name for the new layer Use the delimeter box to specify what the delimeter is for your file e g space commar or tab Note this box accepts regex entries so use lt for tab and Delimited text file nan gnis_no_east_hemi_tabbed txt Layer name Delimiter t 49 QGIS User Guide Version 0 7 Figure 9 10 Selecting the X and Y Fields Greate a Layer from a Delimited Text File REA ni ACE Delimited Text Layer CET e GA bape ier lergitut iatieu We topes ase mM i Description Select the file containing delimited text with lat lon coordinates that you would like to use as a point layer and this plugin will do the job for you Use the layer name box to specify the legend name for the new layer Use the delimeter box to specify what the delimeter is for your file e g space commar or tab Note this box accepts regex entries so use t for tab and ennan After chancina a dalimatar_nrace tha narea KM Delimited text file ran gnis_no_east_hemi_tabbed bxt Layer name Geographic Names Delimiter t X field longdec Iz Y field latdec Help Parse Add Layer Close Figure 9 11 Delimited Text Layer Ad
3. make install 7 As root create the postgres user and setup the database following taken from PostgreSQL INSTALL file with modification e Create the postgres user adduser postgres Create the directory for the PostgreSQL database mkdir usr local pgsql data Change ownership of the data directory to the postgres user chown postgres usr local pgsql data su to the postgres user or login as postgres su postgres Change to the PostgreSQL install directory cd usr local pgsql e Initialize the database 61 QGIS User Guide Version 0 7 bin initdb D usr local pgsql data e Start the PostgreSQL daemon bin pg_ctl start o i D usr local pgsql data 1 home postgres serverlog e Create the test database bin createdb test 8 PostgreSQL should now be running Logon as the postgres user or use su postgres You should be able to connect to the test database and execute a test query with the following commands psql test select version version PostgreSQL 8 0 1 on i686 pc linux gnu compiled by GCC gcc GCC 3 3 1 SuSE Linux 1 row q 9 PostgreSQL install is done C 4 GEOS Note As of version 0 6 GEOS is a requirement in order to build QGIS QGIS uses GEOS to properly fetch features from the the underlying datastore when doing an identify or select operation To install GEOS 1 Download GEOS source from http geos refractions net 2 Untar GEOS tar xzf geos
4. Quantum GIS User Guide Version 0 7 Seamus Gary E Sherman Tim Sutton Radim Blazek GRASS Lars Luthman GPS Plugin August 2005 CONTENTS 1 Forward 1 LI Major Features o cousi d de ee eR Hee PMS o o e o ds 1 TD Whats Mew im sed ca a eRe A E E AR GIGAS Y A 2 2 Introduction To GIS 3 21 Why is all thisso mew iso a thd A ee ee ee ar Ha Ew ae 3 milk Raster Data AAA alata en is ee ee OR SR ROR Re ee OH OOS SBS 4 Bale Vector Data oii a A ee Oe ES a a 4 3 Getting Started 6 ol ic s se 0 44440 eee Gee a Pee bah eee Phe BERD die de Rae 6 oe Sampe Date lt lt cca pk ee ee eee ERR eR RAYA BE A E ARG AR a A 6 So Starting GIS orgu owas ee wee ee Ee eee Oe a A 6 33 1 Command Line OPHANS o soi a ae nn a Seb hana wea adas 6 BA The OGIS Mam Window sa se daca bodies e EEE ELGG ae 7 34 1 The QGIS memu bar 2 8 ek a A eee A AA BE 8 342 Toolbar Storck ea ak a kk ee eae RG ee eRe Soe i Be ears 8 34 3 The QGIS map legend a ee Ee ee Ae a ee 8 344 The QGIS MAP view cc ek es ee ee Re Be eee ee ee ee 9 345 The QGIS map overview o es o c ccs eels dr ee eee eee ea ea dee 9 34 6 The QG S map status bar 2 2 48 68068503 RA DORR REE a 9 oo REMOS 66 ota e a OOO Re SS SRS ee eee Sa 9 3 0 1 Scale Dependent Rendering o cc qa eee wee dad wa ee ea a 10 3 5 2 Controlling Map Rendering ooo ee ee ee Ee wee ew a 10 Dd mboppme Rendering ses a AA AA A BRR 10 3 5 4 Suspending Rendering lt lt ve vea eee EE ee es 10 35 5 Setting
5. a Green Green 3 Blue Blue El OK Cancel 25 QGIS User Guide Version 0 7 5 4 1 Symbology Tab QGIS supports three forms of raster layers e Single Band Grayscale Rasters e Palette Based RGB Rasters e Multiband RGB Rasters From these three basic layer types eight forms of symbolised raster display can be used Single Band Grayscale Single Band Pseudocolor Paletted Grayscale where only the red green or blue component of the image is displayed gt NN Aa Paletted Pseudocolor where only the red green or blue component of the image is displayed but using a pseudocolor algorithm Paletted RGB Multiband Grayscale using only one of the bands to display the image Mulitiband Pseudocolor using only one of the bands shown in pseudocolor Multiband RGB using any combination of three bands COND Oo QGIS can invert the colors in a given layer so that light colors become dark and dark colors become light Use the Invert Color Map checkbox to enable disable this behavior 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 The transparency can also be set using the transparency slider in the layer context menu which is accessible by right clicking on the layer in the legend QGIS can restrict the data dis
6. 10 options 11 scale dependent 10 suspending 10 update during drawing 11 scale 10 security 15 settings 15 shapefile 12 format 12 loading 12 specification 12 spatial index GiST 18 PostGIS 18 shapefiles 13 SPIT 17 editing field names 17 importing data 17 loading 17 reserved words 17 symbology changing 19 71 toolbars 8 vector layers properties dialog 18 renderers continuous color 19 graduated marker 19 graduated symbol 19 single marker 19 single symbol 19 unique value 19 unique value marker 19 symbology 19 renderers see renderers WKT 28 zoom mouse wheel 9
7. 4 S444 oelee aa eee A 35 14 CRASHING PLUGINS e sido ee kn ed bh RH Aw BR A ER 40 15 PLUGINS SETTINGS SAVED TO PROJECT oscuro rasa ed wae ear 41 lv CHAPTER 1 Forward 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 traditionaly expensive commerical 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 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 that point in its evolution and is being used by many for their daily GIS data viewing needs QGIS supports a number of raster and vector data formats with new support easily added using the plugin architecture see Appendix A for a full list of currenly supported data formats QGIS is released under the GNU Public License GPL Developing QGIS under this license means that you can if you want to inspect and modify the source code and guarantees that you our happy user will always have access
8. a map composer and better integration with GRASS The major new features in this release include Be OOS eS FOE E OS E 10 11 12 On the fly projection for reprojecting layers in different coordinate systems Map Composer for creating print layouts Toolbox for running GRASS tools from QGIS Raster graphing tool to produce a histogram for a raster layer Raster query using the identify tool to get the pixel values from a raster New customizable settings for the digitizing line width color and selection color New symbols for use with point layers are available from the layer properties dialog Spatial bookmarks allow you to create and manage bookmarks for an area on the map Measure tool to measure distances on the map with both segment length and total length displayed as you click GPX loading times and memory consumption for large GPX GPS files has been drastically reduced Digitizing enhancements including the ability to capture data straight into PostgreSQL PostGIS and improvements to the definition of attribute tables for newly created layers Raster Georeferencing plugin can be used to generate a world file for a raster by defining known control points in the raster coordinate system CHAPTER 2 Introduction To GIS A Geographical Information System GIS is a collection of software that allows you to create visualise query and analyse geospatial data Geospatial data refers to information about the geographic locat
9. 150 09972 tyonek d 1 nel a b mountain 59 52889 135 28333 skagway c 1 swl apw dam number 2 60 53 145 75167 cordova c 5 swl apw reservoir 60 53167 145 75333 cordova c 5 swl apw reservoir 60 53 145 75167 cordova c 5 sw aaron creek 56 37861 131 96556 bradfield canal b 6 aaron island 58 43778 134 81944 juneau b 3 nel aats bay 55 905 134 24639 craig d 7 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 46 QGIS User Guide Version 0 7 2 The first row is the header row It contains the fields name latdec longdec and cell 3 No quotes are used to delimit text fields 4 The x coordinates are contained in the longdec field 5 The y coordinates are contained in the latdec field 9 3 2 Using the Plugin To use the plugin you must have QGIS running and use the Plugin Manager to load the plugin Start QGIS then Open the Plugin Manager by choosing the Tools Plugin Manager menu The Plugin Manager displays a list of available plugins Plugins that are already loaded have a check mark to the left of their name Click on the checkbox to the left of the Add Delimited Text Layer plugin and click Ok to load it as shown in Figure 9 6 Figure 9 6 Plugin Manager Dialog OGIS Plugin Manger Plugin Directory home gsherman qgiso2 lib agis i To load a plugin click the checkbox next to the plugin and click Ok Name V
10. 2 0 0 tar gz 3 Change to the GEOS source dir cd geos 2 0 0 62 QGIS User Guide Version 0 7 4 Follow the instructions in the GEOS README file to complete the installation Typically the install goes like this configure make make install C 5 PostGIS NOTE You must edit the PostGIS Makefile and make sure that USE_GEOS 1 is set Also adjust GEOS_DIR to point to your GEOS installation directory 1 Download PostGIS source from http postgis refractions net 2 Untar PostGIS into the contrib subdirectory of the PostgreSQL build directory The contrib subdirec tory is located in the directory created in step 3 of the PostgreSQL installation process 3 Change to the postgis subdirectory 4 Edit the Makefile to enable GEOS support see the note above 5 PostGIS provides a manual in the doc html subdirectory that explains the build process see the Installation section 6 The quick and dirty steps to install PostGIS are cd contrib gunzip postgis 1 0 2 tar gz tar xvf postgis 1 0 2 tar cd postgis 1 0 2 make make install createlang plpgsql yourtestdatabase psql d yourtestdatabase f lwpostgis sql psql d yourtestdatabase f spatial_ref_sys sql The better way to install PostGIS is to carefully follow the instructions in the PostGIS manual in the doc html subdirectory or the online manual at http postgis refractions net docs C 6 GRASS If you want QGIS to support GRASS vector and raster layers
11. CHAPTER 5 Working with Raster Data QGIS supports a number of raster data formats This section describes how to work with raster data in QGIS 5 1 What is raster data indexrasters definition 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 datasets 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 In GIS a raster layer would have georeferencing data associated with it which will allow it to be positioned correctly in the map display to allow other vector and raster data to be overlaid with it QGIS makes use of georeferenced rasters to properly display the data 5 2 Raster formats supported in QGIS QGIS supports a number of different raster formats Currently tested formats include e Arc Info Binary Grid e Arc Info ASCII Grid e Grass Raster e Geo TIFF 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 but have not yet been tested See Appendix A 2 for more details 5 3 Loa
12. For data supported by OGR QGIS relies on the presence of a format specific means of specifying the coordinate system In the case of shapefiles this means a file containing the Well Known Text WKT specification of the the coordinate system The projection file has the same base name as the shapefile and a prj extension For example a shapefile named lakes shp would have a corresponding projection file named lakes prj 6 2 Getting Started At startup QGIS does not have On the Fly OTF projection enabled To use OTF projection you must open the Project Properties dialog select a projection for the map and enable projections There are two ways to open the Project Properties dialog 1 Select Project Properties from the Settings menu 2 Click on the projector icon in the lower right hand corner of the statusbar Tip 10 PROJECT PROPERTIES DIALOG If you open the Project Properties dialog from the Settings menu you must click on the Projection tab to view the projection settings Opening the dialog from the projector icon will automatically bring the Projection tab to the front The Projection dialog contains four important components as numbered in Figure 6 1 and described below 28 QGIS User Guide Version 0 7 Figure 6 1 Projection Dialog OS X Project Properties L Enable on the fly projection i Projection 2 Geographic Coordinate System wProjected Coordinate System wAlbers Equal Area NAD 27 Ala
13. The digitizing tools for GRASS vector layers are accessed using the Edit GRASS Vector Layer tool 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 In this release the vector must exist prior to beginning to edit The ability to create a new empty layer will be added in a future version Figure 7 1 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 7 4 1 Toolbar Table 7 1 lists the digitizing tools provided by the GRASS plugin These correspond to the tool buttons in the toolbar s across the top of the dialog 33 QGIS User Guide Version 0 7 Figure 7 1 GRASS Edit Dialog VOBD O gt ewe Category Settings symbology Table Mode Next not used 5 Table 7 1 GRASS Digitizing Tools Category Field layer fa Tool Purpose New Point digitize new point 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 select one vertex of existing line or boundary and identify new position Add vertex add a new vertex to existing line Delete vertex delete one vertex from existing line confirm selected vertex by another click Move line select ex
14. The map is linked to the QGIS map canvas If you change the view on the map canvas by zooming or panning you can update the map composer view by selecting the map in composer and clicking on the Set Extent button You can also change the composer view by specifying a map scale To set the view to a specific scale 1 Choose Scale calculate extent from the Set drop down box 2 Enter the scale denominator in the scale box 3 Press Enter 36 QGIS User Guide Version 0 7 Figure 8 1 Map Composer Al ely Fle alajalol a uls Composition Map 1 2 r Paper ___ Size AO 841x1189 mm Resolution dpi 00 8 1 2 Adding other Elements to the Composer m legend can be added to the composer canvas and customized to show only the desired layers To add and you can move it where you like Click on the Items tab to customize the appearance of the legend a legend click on the Add Vector Legend button The legend will be placed on the composer canvas including which layers are shown the segment size number of segments scalebar units size and font for the scalebar C You can add text labels to the composer by clicking on the Add New Label button Use the Item tab while the text is selected to customize the settings or change the default text Figure 8 2 shows the map composer after adding each type of map element 37 QGIS User Guide Version 0 7 Figure 8 2 Map Composer with map view legend s
15. 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 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 LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 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 SERVICING REPAIR OR CORRECTION 12 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AG
16. build QGIS 0 7 Seamus from the source distribution These instructions are for Linux Unix and other POSIX systems which have the required build environment Installing on Windows and Mac OS X is a simple process as described below You don t have to build all the QGIS dependencies from source If your platform provides packages at an acceptable version for the needed dependencies you can install them prior to building QGIS Make sure you also install the development package if separate from the main package for each dependency QGIS needs the header files from these packages in order to build The latest version of this document can always be found at http qgis org docs install html C 1 1 Installing Windows Version Installing the Windows version of QGIS is simply a matter of running the user friendly setup wizard See the README WIN32 file for additional information regarding the Windows version of QGIS At version 0 7 the GRASS plugin is not available in Windows Work on including the plugin in the next version of QGIS is under way C 1 2 Installing Mac OS X Version To install the compressed disk image containing the OSX version of QGIS double click to expand and mount the image then drag QGIS application to your hard drive If you want to build from source on Mac OS X see http wiki qgis org qgiswiki BuildingOnMacOsX Installing the compressed disk image is the easiest method and gives you the full functionality o
17. device type with the download command gpsbabel type i garmin o gpx in out this is actually the download command for the predefined device type Garmin serial and then use it to download waypoints from port dev ttyS0 to the file output gpx QGIS will replace the keywords and run the command epsbabel w i garmin o gpx dev ttyS0 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 9 3 Using the Delimited Text Plugin The Delimited Text plugin allows you to load a delimited text file as a layer in QGIS 9 3 1 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 coordinate system is not important An example of a valid text file might look like this name latdec longdec cel1 196 mile creek 61 89806 150 0775 tyonek d 1 nel 197 1 2 mile creek 61 89472
18. feature tracker 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 may require significant developer effort to remedy and the manpower is not always available for this If you have found a bug and fixed it yourself you can submit it to the QGIS Sourceforge patch queue where someone will review it and apply it to QGIS Please dont be alarmed if your patch is not applied straight away developers may be tied up with other committments There is also a community site for QGIS where we encourage QGIS users to share their experiences and pro vide case studies about how they are using QGIS The community site is available at http community qgis org Lastly we maintain a WIKI web site at http wiki qgis org where you can find a variety of useful information relating to QGIS development release plans links to download sites and so on 51 APPENDIX A Supported Data Formats A 1 Supported OGR Formats At the date of this document the following formats are supported by the OGR library Formats known to work in QGIS are indicated in bold Arc Info Binary Coverage Comma Separated Value csv DODS OPeNDAP ESRI Shapefile FMEObjects Gateway e GML IHO S 57 ENC Mapinfo File Microstation DGN OGDI Vectors e ODBC Oracle Spatial PostgreSQL e SDTS SQLite e UK NTF e U S Census TIGER Line e VRT Virtual Datasource A 2 GDAL Raster Form
19. layer is drawn to the map view 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 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 3 5 below At the far right of the status bar is a projector icon Clicking on this opens the projection properties for the current project 3 5 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 QGIS User Guide Version 0 7 e Adding a layer e Panning or zooming e Resizing the QGIS window e Changing the visibility of a layer or layers QGIS allows you to control the rendering process in a number of ways 3 5 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 General tab set the minimum and maximum scale values and then click on the Use scale dependent rendering 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 3 5 2 Controlling Map Rendering Map rendering can be controlled in the following ways 1 Stoppin
20. m QGIS aa ca is s saana oa EEK Re Ee eS 5 3 Loading raster data in QGIS ocre ara a a ee ww ee ae DA Raster Froper ioe nio as a RR e AAA O EA BALL Symbology Tab sa accostata a a ee AA Bae Genera abi so aaa eee eK Oe we Bee ee Ad DAS Metadata TaD ic dod do ee Re e Se OS Ae gd wae A OA Pyramids Tabo iia BOER wae A Oe eS Working with Projections 6 1 Overview of Projection Support s sonnis 4444 225 eee a eee eS 02 Getting Started te a A a gb ee A a ee ew a ae O21 specie a Projechon ooo ks ee eg a oe OG ae A 63 Custom Projections 3 22 0 tae ba pe eR Re EEE TEER ESE LEE GRASS Gl Btartmg QGIS with GRADS gt s o ka ese da eee ee ew eee a oe ee ee fl From GRASS Shell ui ee eee ee POPE EE RRA Se Gee 71 2 Outside GRASS shell 1 4 45 4 e454 ide di we dba eee Aaa eS Ta Loain GRASO Date ee oen aad a RR A ee Hee SiG wae Ta Vector Data Model oo 84 bee eee eb ed ee EEE A a ee eee es TA Digitizing and Editing Tools skh e ee a b a Be ee we ee BS oS ae A TOGIDS s 000004 oe baa oe a a bee bedded AQ Category Tab oda SR EE Roe es be tae ee een ed oS TAS Settings Ta eg aaea a das ee RR A et ae a a TA Symbolosy TaD o e re soraa eG eRe eee ee Re ee ee a a A TS FENG Sock BAe ee eh ee Re aa OS PE Se ee dde Gee eed TAG Recon Toolea aaa IIA Map Composer s1 Using Map Composer aice a 00 See eee eee DIA A e e Fores 8 1 1 Adding a Map to the Composer 8 1 2 Adding other Elements to the Composer o o Boll Other R
21. program script or command Double quotes will be ignored if proceeded by a backslash 19 QGIS User Guide Version 0 7 Figure 4 4 Vector Layer Properties Dialog Layer Properties Symbology General Metadata Labels Actions Legend type Single Symbol M Label l O m Outline Style Outline color ka Outline Width Fill Color MS m Fill Patterns z M i 1 C E Apply OK J Cancel Two example actions are shown below 1 konqueror http www google com search g nam 2 konqueror http www google com search q In the first example the web browser konqueror is invoked and passed a URL to open The URL performs 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 path 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 4 4 2 Using Actions Actions can be invoked from either the Identify Results dialog or th
22. 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 are used behind the scenes when a corresponding data type is added as a layer in QGIS 9 1 4 Core Plugins QGIS currently contains 9 core plugins that can be loaded using the Plugin Manager Table 9 1 lists each of the core plugins along with a description of their purpose Figure 9 2 shows the icon for each plugin in the Plugin toolbar the number corresponds to the Ttem in Table 9 1 Note the GRASS plugin is not included below because it installs its own toolbar see Section 7 for a discussion of available features in GRASS plugin Tip 15 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 it 41 QGIS User Guide Version 0 7 Table 9 1 QGIS Core Plugins Item Plugin Description 1 Copyright Label Display a copyright label on the map canvas 2 Delimited Text Load a delimited text file containing x y coordinates as a point layer 3 GPS Tools Load and display GPS data 4 Graticule Creator Create a latitude longitude grid and save as a shapefile 5 Scalebar Add a scalebar to the map canvas 6 North Arrow Add a north arrow to the map canvas 7 PostgreSQL Geoprocessing Buffer a PostGIS layer
23. the symbology for a layer simply double click on its legend entry and the vector layer properties dialog will be shown 4 4 Attribute Actions 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 4 4 1 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 Actions 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
24. to the QGIS source directory You have two options for building and installing QGIS Quick and Dirty and the right way 66 QGIS User Guide Version 0 7 C 11 1 Quick and Dirty If you don t need PostgreSQL support and have installed GDAL you can configure and build QGIS by changing to the distribution directory and typing configure make make install The above assumes that the gdal config program is in your PATH See the next section for the full configu ration instructions C 11 2 Configuring QGIS the Right Way To see the configure options available change the the QGIS directory and enter configure help Among other options there are three that are important to the success of the build with qtdir DIR Qt installation directory default QTDIR with gdal path gdal config Full path to gdal config script e g with gdal usr local bin gdal config with pg path pg_config PostgreSQL PostGIS Support full path to pg_config with grass DIR GRASS Support full path to GRASS binary package Qt The configure script will detect Qt unless it is installed in a non standard location Setting the QTDIR environment variable will make ensure that the detection succeeds You can also specify the path using the with qtdir option GDAL If the gdal config script is in the PATH configure will automatically detect and configure GDAL support If not in the path you can specify the full path to gda
25. to the map will be off invisible by default 3 5 6 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 Preferences from the Settings menu and click on the Rendering tab Set the feature count to 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 11 CHAPTER 4 Working with Vector Data QGIS supports vector data in a number of formats including shapefiles MapInfo mif and PostGIS layers in a PostgreSQL database Support for additional data types is provided by plugins for example delimited text This section describes how to work with two common formats shapefiles and PostGIS 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 4 1 Shapefiles Shapefile support is provided by a library of functions OGR http www remotesensing org gda1 ogr See Appendix A 1 for a list of supported formats A shapefile actually consis
26. 8 SPIT Shapefile to PostGIS Import Tool import shapefiles into PostgreSQL Figure 9 2 Plugin Toolbar and Icons 000000090 opa 109m 9 2 Using the GPS Plugin 9 2 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 waypoints 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 9 2 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 need to use the GPS Tools plugin When this plugin is loaded a button with a small handheld GPS device will show up in the toolbar the device looks a bit like a mobile phone Clicking on this button will open the GPS Tools dialog see figu
27. GRASS shell GRASS started by grass57 command no additional settings are required 7 1 2 Outside GRASS shell If QGIS is not started from the GRASS shell the environment variables must be properly set before starting QGIS The path to GRASS libraries must be added to LD_LIBRARY_PATH environment variable For example in bash export LD_LIBRARY_PATH usr1 grass57 dist i686 pc linux gnu lib LD_LIBRARY_PATH The GISBASE environment variable must be set to the full path of the directory where GRASS is installed the same as used for with grass option For example in bash export GISBASE usri grass57 dist i686 pc linux gnu 7 2 Loading GRASS Data With the GRASS plugin loaded you can load a vector or raster layer using the appropriate button on the toolbar 32 QGIS User Guide Version 0 7 Tip 11 GRASS DATA LOADING If you have problems loading data or QGIS terminates abnormally check to make sure you have started GRASS properly as described in Section 7 1 7 3 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 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 boundari
28. IS with the countries Shapefile Loaded Quantum GIS 0 7 0 Seamus File View Layer Settings Plugins Help la BBS lo ov Scale 1 2598 Passs 9so 1 Render y A 4 pal to load a polygon layer 4 2 PostGIS Layers PostGIS layers are stored in a PostgreSQL database The advantage of PostGIS is the spatial indexing filtering and query capability Using PostGIS vector functions such as select and identify work more accurately than with OGR layers in QGIS To use PostGIS layers you must Create a stored connection in QGIS to the PostgreSQL database if one is not already defined Connect to the database Select the layer to add to the map Optionally provide a SQL where clause to define which features to load from the layer oF WwW Ne Load the layer 4 2 1 Creating a Stored Connection 14 QGIS User Guide Version 0 7 Ss 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 Add a PostGIS Layer toolbar button The Add PostGIS Table s dialog will be displayed To access the connection manager click on the New button to display the Create a New PostGIS Connection dialog The parameters required for a connection are shown in Table 4 1 Table 4 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 t
29. It is impossible to edit vectors in mapsets which are not yours even if you have write permissions 7 4 6 Region Tool The current region window in GRASS is very important for all raster modules All new created rasters have the extension and resolution of the current region regardless their original region The region is stored in LOCATION MAPSET WIND file and it defines north south east west number of columns number of rows horizontal and vertical resolution It is possible to switch on off the grass region in QGIS canvas using the Display Current GRASS Region button With the Edit Current GRASS Region you can open a tool in which you can change the current region and symbology of the rectangle on the QGIS Canvas When the tool is running it is also possible to select a new region interactively on the QGIS canvas Both tools are available only if QGIS was started from a GRASS shell or if the GISRC environment variable pointing to a valid GISRC file was set i e only if you are running GRASS within your mapset 35 CHAPTER 8 Map Composer The map composer is a feature that provides improved layout and printing capabilities The composer allows you to add elements such as the QGIS map canvas legend scalebar and text You can size and position each item and adjust the properties to create your layout The result can be printed exported as an image or exported to SVG To access the map composer click on the P
30. Layer Add Option cc cc ee ee be ee Pe ee a PSS SS 11 3 5 6 Updating the Map Display During Rendering 11 4 Working with Vector Data 12 Al Bhape les co co 3404 44 SAPS EYEE REESE Eee EEE ERE a a a a a 12 11 Loading a Dhapeble ooo sec prag naea d eoh Boa aa ee ee i a E a 12 4 1 2 Loading a Mapluto Layer 4 sasata aa adang a edipa nara a a 13 4 13 Loading an ArcInfo Coverage e aaas a aa doa ee 13 A2 Pastas Mayers eee aiana rs rar a 14 4 21 Creating a Stored Connection a os ee orena eR ee ea Mae ee aes 14 422 Loading a PostGIS Layer serae 44 65 ee ce Rt eee eee PREG REE a wd 15 142 3 Using the Query Builder e as cas tibii 4444484 ewe dae de e da da A 16 4 2 4 Some details about PostgreSQL layers 0 02 2 2 00 a 17 4 2 5 Importing Data into PostgreSQL og cce i e eaaa a ee o 17 Eb Jmiproving Perormance uds rg oe oh ed A Oe Ra 18 4 3 The Vector Properties Dialog s cn e scs 68 Dede a add eee a es 18 Ll Vector Syabology coo e sek a ee TOS ELEM a 19 14d Attubite ACOS aaa a ee a it eee ae ae a 19 44 1 Dopning AGHONS 0 fas na a ee hE EE Oe a 19 AAD Usome AGUAS da A oe AA AAA Gears AD EME 2 624435 ba a dt bone are tot dened eee cc eS 451 Editing an Boasting Layers ioc ca dd dine eee RADAR ES OS eB 4 0 2 Crestme a New layer oa aa rat fe o a a ee Be SERRE SS REED DSS Working with Raster Data 5 1 What is taster data ooo oo co E454 444 Bede a ba eae ees 5 2 Raster formats supported
31. NetCDF OGDI Bridge PCI aux Labelled PCI Geomatics Database File Portable Network Graphics png Netpbm ppm pgm USGS SDTS DEM CATD DDF SAR CEOS USGS ASCII DEM dem X11 Pixmap xpm 2GRASS raster support is supplied by the QGIS GRASS data provider plugin 53 APPENDIX B Gnu 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 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
32. QL 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 for more information The following is an example of creating a GiST index gsherman madison current psql gis_data Welcome to psql 8 0 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 VACUUM gis_data Xq gsherman madison current 4 3 The Vector Properties Dialog The vector properties dialog provides information about a 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
33. REED TO IN WRITING WILL ANY COPYRIGHT HOLDER OR ANY OTHER PARTY WHO MAY MODIFY AND OR REDISTRIBUTE THE PRO 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 57 QGIS User Guide Version 0 7 B 1 Quantum GIS Qt exception for GPL In addition as a special exception the QGIS Development Team gives permission 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 58 APPENDIX C QGIS Installation Guide C 1 Introduction The majority of this document is devoted to describing how to
34. The minimum recommended version for use with QGIS is 1 2 6 2 Untar the distribution tar xfvz path gdal x x x tar gz 3 Change to the gdal x x x subdirectory that was created by step 2 64 QGIS User Guide Version 0 7 cd gdal x x x 4 Configure GDAL configure or if you want GRASS support configure with grass lt full path to grass install gt Depending on the GDAL version you are building it may be necessary to specify without ogdi when running configure if you don t have the OGDI library available on your system 5 Build and install GDAL make su make install 6 In order to run GDAL after installing it is necessary for the shared library to be findable This can often be accomplished by setting LD_LIBRARY_PATH to include usr local lib On Linux you can add usr local lib or whatever path you used for installing GDAL to etc ld so conf and run ldconfig as root 7 Make sure that gdal config found in the bin subdirectory where GDAL was installed is included in the PATH If necessary add the path to gdal config to the PATH environment variable export PATH path gdal config PATH 8 Check the install by running gdal config prefix If you ve had problems during the installation refer to this manual where the whole process is described with some more detail http www remotesensing org gdal gdal_building html C 10 Qt Qt 3 2 1 or higher is required in order to co
35. You can select multiple layers by holding down the shift key while clicking See Section 4 2 3 for information on using the PostgreSQL Query Builder to further define the layer 5 Click on the Add button to add the layer to the map Tip 6 PosTGIS LAYERS Normally a PostGIS layer is defined by an entry in the geometry_columns table At version 0 7 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 15 QGIS User Guide Version 0 7 4 2 3 Using the Query Builder The PostgreSQL Query Builder allows you to define a subset of a table and add it as a layer in QGIS 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 4 3 shows an example of the query builder populated with data from a layer in PostgreSQL Figure 4 3 PostgreSQL Query Builder Postgre SQL Query Builder Table public akmils in database test on host localhost user gsherman Fields Values feldspar fluorine gemstone geothermal graphite Sample All Operators Jl lt gt J uke im Noti lt gt 1 J we and or nor mSQL where clause Clear Test Ok Cancel The qu
36. a E 59 Gl Gaia GTi ek ee a a E Oe ee PEE ee ee da ek e E a 60 Co Pone SO vse a a tate dd ne ed he HE ODS o ee ea ed 60 CA GEOS o a a ad Sees Ne a aA A SE AAA ER BR RRA EE FA 62 E aeoo a ae 644 29 b hie daoiae te YB ay ay ee ee le eee eater an a dS 63 CO CRASS a We ak ae ed Sa a eS ee oo Bo a ee ee ee A 63 G7 Prok os eee eG hha li a ee eee pe da ded eee ee bbbe pened daa 64 AAN 64 Co OSI opi da aa dar aa 64 AAA AAA A 65 GA Bulma QGIS 2 2900 e bt a de E ES 66 CALI Quick and THY ess aacra Gee eb bb edi dda as AAA a a ead 67 C 11 2 Configuring QGIS the Right Way lt ee ee 67 CIZ Buldmg PGMS ccoo we dd dE eee PS POW OME OEE eee Sa 4 69 QGIS Tips 1 EXAMPLE USING COMMAND LINE ARGUMENTS 1 ee ee a 7 2 VIEWING THE LAYER MENU 2 024 eeoa cen ha oe ee BOOS eee ee eS 8 3 ZOOMING THE MAP WITH THE MOUSE WHEEL 9 4 LAYER COLORS o oa ce ka dos A a a a e dd we 12 5 OGIS USER SETTINGS AND SECURITY 2 056448 404508 a RA A a A 15 6 POSTGIS LAYERS vo donala aa wa ies a a EIA ewe we see ee are 15 7 CHANGING THE LAYER DEFINITION 0 1 1 1 g eag g a a a 16 8 IMPORTING SHAPEFILES CONTAINING POSTGRESQL RESERVED WORDS 17 9 GATHERING RASTER STATISTICS o 6 2 soose ee E Ea ee a il 10 PROJECT PROPERTIES DIALOG o e es dae aer aa RAR ARR RR RR RR ee A 28 IT GRASS DATA LOADING gt o soea mace Oe Ge ee we eS Oe ae ee ew eH 33 12 LEARNING THE GRASS VECTOR MODEL 33 is GRASS EDIT PERMISSIONS soon
37. all 68 QGIS User Guide Version 0 7 NOTE You must do a make install and start QGIS from the installed location In the case of the example above the QGIS binary resides in the bin subdirectory of the directory specified with the prefix option usr local qgis bin For information on using QGIS see the QGIS User Guide C 12 Building Plugins The QGIS source distribution contains a number of core plugins These are built along with QGIS using the instructions above Additional external plugins are available from the QGIS community website at http community qgis org Instructions for building an external plugin can be found at http wiki qgis org qgiswiki StepByStepBuildInstructions Some external plugins may include instructions on building If so follow the instructions provided with the plugin rather than those provided in the wiki 69 INDEX 19 actions 19 defining 19 examples 20 using 20 attribute actions see actions command line options 6 crashes 40 data sample 6 data providers 41 delimited text 12 editing 21 an existing layer 21 creating a new layer 22 icon 21 saving changes 21 EPSG 28 GRASS 32 attribute linkage 33 attribute storage 33 category settings 34 digitizing 33 digitizing tools 33 34 edit permissions 35 environment settings 32 loading data 32 region 35 display 35 editing 35 shell 32 snapping tolerance 35 starting QGIS 32 symbology sett
38. als refer to the six major areas of the interface as discussed below Figure 3 1 Main window Quantum GIS 0 7 0 Seamus File View Layer Settings Plugins Help Qik liad 19 PES Sod RaZ I A gt JOS t EJES LLELE Y c QGIS 2005 Scale 1 6982307 195033 1607854 6 1 Render 4 NOTE YOUR WINDOW DECORATIONS TITLE BAR ETC MAY APPEAR DIFFERENT DEPENDING ON YOUR OPERATING SYSTEM AND WINDOW MANAGER The QGIS main window is divided into six areas 1 The menu bar QGIS User Guide Version 0 7 The tool bar The map legend The map view The map overview The status bar A oe BS These six components of the QGIS interface are described in more detail in the following sections 3 4 1 The QGIS 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 functions provided are File project open save export image properties View zoom refresh Layer add show hide layers Settings plugin manager preferences Plugins menus added by plugins as they are loaded Help documentation and web links 3 4 2 Toolbars The toolbars provide access to most of the same functions as the menus plus additional tools 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 You can also use the Whats This tool t
39. ats At the date of this document the following formats are supported by the GDAL library Note that not all of these format may work in QGIS for various reasons For example some require external commercial libraries Only those formats that have been well tested will appear in the list of file types when loading a raster into QGIS Other untested formats can be loaded by selecting the All other files filter Formats known to work in QGIS are indicated in bold e Arc Info ASCII Grid e Arc Info Binary Grid adf e Microsoft Windows Device Independent Bitmap bmp e BSB Nautical Chart Format kap e VTP Binary Terrain Format bt 1QGIS implements its own PostgreSQL functions OGR should be built without PostgreSQL support 52 QGIS User Guide Version 0 7 CEOS Spot for instance First Generation USGS DOQ doq New Labelled USGS DOQ doq Military Elevation Data dt0 dt1 ERMapper Compressed Wavelets ecw ESRI hdr Labelled ENVI hdr Labelled Raster Envisat Image Product n1 EOSAT FAST Format FITS fits Graphics Interchange Format gif GRASS Rasters TIFF GeoTIFF tif Hierarchical Data Format Release 4 HDF4 Erdas Imagine img Atlantis MFF2e Japanese DEM mem JPEG JFIF jpg JPEG2000 jp2 j2k JPEG2000 jp2 j2k NOAA Polar Orbiter Level 1b Data Set AVHRR Erdas 7 x LAN and GIS In Memory Raster Atlantis MFF Multi resolution Seamless Image Database MrSID NITF
40. calebar and text added The map view is currently selected note the blue rectangles in each corner Quantum GIS Map Composer Extent calculate scale Legend Majrivers Width EY bakes EJ Maska 826 Height 725 8 1 3 Other Features The map composer has navigation tools to zoom in and out To zoom in click the zoom in tool The map composer canvas will be scaled by a factor to 2 Use the scrollbars to adjust the view to the area of interest Zooming out works in a similar fashion If you find the view in an inconsistent state you can use the refresh button to redraw the map composer 38 QGIS User Guide Version 0 7 canvas 8 1 4 Creating Output The map composer allows you to print the map to a printer export to a PNG or export to SVG Each of these functions is available from the composer toolbar 39 CHAPTER 9 Using Plugins 9 1 An Introduction to Using Plugins QGIS has been designed with a plugin architecture This allows new features functions to be added to the application Many of the features in QGIS are actually implemented as plugins There are two types of plugins in QGIS core and user contributed A core plugin is maintained by the QGIS development team and is part of every QGIS distribution A user contributed plugin is an external plugin that is maintained by the individual author The QGIS Community site http community qgis org serves as the repository for user cont
41. ded to QGIS Quantum GIS 0 1 0devel34 Pumpkin File View Tools Delimited Text Launcher Help 174 08954442 68 2282088602 50 CHAPTER 10 Help and Support QGIS is still under active development and as such it won t always work like you expect it to The pre ferred way to get help is by joining the qgis users mailing list Your questions will reach abroader audi ence and answers will benefit others You can subscribe to the qgis users mailing list by visiting here http lists sourceforge net lists listinfo qgis user 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 sourceforge net lists listinfo qgis developer 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 andit may take a while for them to notice your question Commercial support for QGIS is available from Micro Resources While the qgis users mailing list is useful for general how do I 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 When reporting a bug either login to SourceForge or if you don t have a SourceForge id provide an email address where we can request additional information Feature requests can be submitted using the
42. ding raster data in QGIS T Raster layers are loaded either by clicking on the Load Raster icon or by selecting the View gt Add Raster Layer menu option More than one layer can be loaded at the same time by holding down the Control key and clicking on multiple items in the file dialog 24 QGIS User Guide Version 0 7 5 4 Raster Properties To view and set the properties for a raster layer right click on the layer a name This displays the raster layer context menu that includes a number Zoom to extent ofselected layer of items that allow you to Properties Show In Overview e Zoom to the full extent of the raster Remove e Show the raster in the map overview window Transparency Open the properties dialog of course Remove the layer from the map Set the transparency using a slider control Choose Properties from the context menu to open the raster properties dialog for the layer Figure 5 1 shows the properties dialog There are four tabs on the dialog Symbology General Metadata and Pyramids Figure 5 1 Raster Layers Properties Dialog Raster Layer Properties Symbology General Metadata Pyramids Show As a Three Band O Single Band Paletted Image Notes This image uses a fixed color palette You can remap these colors in different combinations e g Red blue in image Green blue in image Blue green in image Appearance RGB Invert Color Map Color Band Transparency Red Red I
43. e Attribute table dialog 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 20 QGIS User Guide Version 0 7 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 that you wish to pass to the application or script Here is another example that pulls data out of a vector layer and inserts it into a file using bash and the echo command so it will only work on Gnu Linux and perhaps Mac OS X The layer in question has fields for a species name taxon_name latitude lat and longitude long I would like to be able to make a spatial selection of a localities and export 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 lat 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 Acacia mearnsii 34 0800000000 150 0800000000 Acacia mearnsii 34 9000000000 150 1200000000 Acacia mearnsii 35 2200000000 149 9300000000 Acacia mearnsii 32 2700000000 150 4100000000 4 5 Editing QGIS supports basic capabilities for editing spatial data Before reading any further yo
44. e following 55 QGIS User Guide Version 0 7 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 corresponding 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 distribution 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 executable 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 syst
45. e projection parameters Figure 6 2 shows the dialog with an example projection The parameters shown were entered based on a knowledge of the projection and the information found in OF90 284 You can test your projection parameters to see if they give sane results by clicking on the Test tab and pasting your projection parameters into the Parameters field Then enter known WGS 84 latitude and longitude values in North and East fields respectively Click on Calculate and compare the results with the known values in your projected coordinate system 30 QGIS User Guide Version 0 7 Figure 6 2 Custom Projection Dialog OS X 09e wf Custom Projection Definition Test Custom Projection Definition You can define your own custom projection here The definition must conform to the proj4 format for specifying a Spatial Reference System Name albers test Parameters proj aea lat_1 55 lat_2 65 lat_0 50 lon_0 154 x_0 0 y_0 0 ellps clrk66 datum NAD27 le lt lofl gt gt I New Save Delete Close 31 CHAPTER 7 GRASS The GRASS plugin adds the following features to QGIS e Add GRASS vector layers e Add GRASS raster layers e Vector layers digitizing e Changing of the GRASS region 7 1 Starting QGIS with GRASS When using the GRASS plugin QGIS can be started in two ways from the GRASS shell or from a regular shell 7 1 1 From GRASS shell If QGIS is started from the
46. e the original data is stored to build pyramids 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 27 CHAPTER 6 Working with Projections QGIS supports on the fly projection of vector layers This feature allows you to display layers with different coordinate systems and have them overlay properly 6 1 Overview of Projection Support QGIS has support for approximately 2 700 known projections Projections 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 projections are stored in a user database See Section 6 3 for information on managing your custom projections The projections available in QGIS are based on those defined by EPSG and are largely abstracted from the spatial_references table in PostGIS version 1 x Note that the identifiers used in QGIS do not correspond to the EPSG or PostGIS spatial reference identifiers The EPSG and PostGIS identifiers are present in the database and can be used to specify a projection in QGIS In order to use OTF projection your data must contain information about its coordinate system For PostGIS layers QGIS uses the spatial reference identifier that was specified when the layer was created
47. eais ova aaa dar daa Sola resting OIDO coa A a SA A eee a Sd Using Plugins 91 An Introduction to Using Pigs oo cons a eR RE eee 91 1 Finding and Installing a Plugin e e vu u racet ie De GS we ee es Dal Managing PINES lt lt a a e AAA Ys a a Se DL Data Providers y sai aa aa a Gd aa a a a a DLA Core PRIISTAS oa oa s ea Re a AAA RARA eS Bas 92 Using the GPS Plugin ociosas by a aa a a e AAA O22 Whats GPS orar adiaka ape d i e e e a e d a RP A A 92 2 Loading GPS data kom afle i466 neseser Pai eRe eee ees O25 a AE 9 2 4 Importing GPS data esci seh ee a ER a ee 9 2 5 Downloading GPS data from a device o 0 000 0 2 6 Uploading GPS data to device cis sg eoa sosa aa eS a De eS Ss 9 2 1 Defining dew devicetypes acia A a a 45 9 3 Using the Delimited Text Plug ociosos oo rro AA 46 93 1 ROQUESMEniS ssl a dd AAA 46 OR Usame o Piva o alado oo a A SE RAMA RR S aS 47 10 Help and Support 51 A Supported Data Formats 52 Aull Supported OGR Formats rra eee be EY ee AE RE a a as 52 A2 GDAL Raster Formats 0000 46 bee ee REARS RR ER Ee RR REG SSS 52 B Gnu Public License 54 B 1 Quantum GIS Qt exception for GPL o dona daite a Eaa aa waaa 58 C QGIS Installation Guide 59 Cal troduction cbr cera ee ee a dd Ree dee 59 CLI Installing Windows Versi n s o 00 ck ee eRe ARE a eS 59 C12 Tostalime Mac OS X Version 2 ee en eae we toes 59 C13 Building mont Sources lidia we a ede ee a
48. em 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 automatically terminate your rights under this License However parties who have received copies or rights from you under this License will not have their licenses terminated 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 licen
49. ersion Description E Add Dalimited Text Layer 0 1 This plugin provides support for delimited text files containing x y coor iza PostgresSOL Geoprocessing Version 0 1 Geoprocessing functions for working with Postgre SQL PostGIS layer o SPIT Version 0 1 Shapefile to Postgre SQL PostGIS Import Tool A Ie A new toolbar icon is now present Click on the icon to open the Delimited Text dialog as shown in Figure 9 7 First select the file to import by clicking on the ellipsis button L Select the desired text file from the file dialog Once the file is selected the plugin attempts to parse the file using the last used delimiter in this case Figure 9 8 In this case the delimiter is not correct for the file The file is actually tab delimited Note that the X and Y field drop down boxes do not contain valid field names To properly parse the file change the delimiter 47 QGIS User Guide Version 0 7 Figure 9 7 Delimited Text Dialog Greate a Layer from a Delimited Text File or ame e Delimited Text Layer Description Select the file containing delimited text with lat lon coordinates that you would like to use as a point layer and this plugin will do the job for you Use the layer name box to specify the legend name for the new layer Use the delimeter box to specify what the delimeter is for your file e g space commar or tab Note this box accepts regex entries so use t for tab and Simi sp 2333355133 en a
50. ery 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 All 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 Test 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 7 CHANGING THE LAYER DEFINITION You can change the layer definition 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 General tab See Section 4 3 for more information 16 QGIS User Guide Version 0 7 4 2 4 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 request However if you have trouble loading a PostgreSQL table into QGIS the information below may help you
51. es and centroids a vector map can also contain points and lines All these geometry elements can be mixed in one vector 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 with different attribute table The ayer of the feature is defined by field sorry for this name Field is the number which defines 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 are stored in external database tables for example DBF PostgreSQL etc Attributes in database tables are linked to geometry elements using category Category key ID is an integer attached to geometry primitives and it is used as the link to one column in the database table Tip 12 LEARNING THE GRASS VECTOR MODEL The best way to learn the GRASS vector model and its capabilities is to download the demo mapset from http mpa itc it radim g51 g51test 12 multi tar gz Extract the mapset add all layers from vector multi to QGIS and query attributes Finally start editing of vector multi to see how those layers are stored 7 4 Digitizing and Editing Tools
52. f QGIS and all plugins including GRASS See the README file included on the disk image for additional instructions C 1 3 Building from Source The remainder of this document deals with compiling and installing QGIS from the source code Specifically this applies to Linux Unix systems At 0 7 there are two new requirements SQLite and Proj4 These must be built and installed prior to configuring QGIS QGIS can be installed with three levels of support for data stores 59 QGIS User Guide Version 0 7 1 Basic raster and vector support GDAL and OGR formats 2 PostreSQL GEOS PostGIS 3 GRASS raster and vector support Basic support uses the GDAL OGR libraries and supports many raster and vector formats For more information on the available formats see http gdal maptools org formats_list html and http gdal maptools org ogr ogr_formats html PostgreSQL PostGIS support allows you to store spatial data in a PostgreSQL database GRASS support provides access to GRASS mapsets Note If you plan to build QGIS with GRASS support version 1 2 6 or higher of GDAL must be used Each of the requirements is discussed below Note that the information given below is abstracted from the installation documentation for each of the libraries See the install information for each library to get detailed instructions In the documentation below the file names and versions used are examples If you are building QGIS without PostgreSQL
53. g rendering during drawing of the map canvas 2 Temporarily suspending rendering 3 Setting an option to control the visibility of layers when they are added 3 5 3 Stopping Rendering To stop the map drawing press the ESC key This will halt the refresh of the map canvas and leave the map partially drawn It may take a bit of time between pressing ESC and the time the map drawing is halted 3 5 4 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 3 5 Examples of when you might want to suspend rendering include e Add many layers and symbolize them prior to drawing e Add one or more large layers and set scale dependency before drawing e Add one or more large layers and zoom to a specific view before drawing e Any combination of the above Checking the Render box enables rendering and causes and immediate refresh of the map canvas 10 QGIS User Guide Version 0 7 3 5 5 Setting Layer Add Option You can set an option to always load new layers without drawing them This means the layer will be added to the map but its visibility checkbox in the legend will be unchecked by default To set this option choose Preferences from the Settings menu and click on the Rendering tab Check the New layers added to the map are not displayed checkbox Any layer added
54. ght 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 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 the discrete geographic location QGIS User Guide Version 0 7 2 Lines Multiple coordinates x1 yl x2 y2 x3 y4 xn yn strung together in a certain order Like drawing a line fro
55. he arrow with a question mark next to it to get more information about the tools and other components of the QGIS interface To use it click on the Whats This button and then click on the item of interest to display the information 3 4 3 The QGIS 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 hide that layer Tip 2 VIEWING THE LAYER MENU You can display the context menu for any layer in the legend by right clicking on the layer name The context menu contains items for working with the layer and viewing its properties Each legend entry can show the following mini icons gt This is a raster layer that has pyramids built for it to improve rendering efficiency see Section 5 4 4 This is a raster that has no pyramid layers see Section 5 4 4 QGIS User Guide Version 0 7 This layer is shown in the overview map area as well as in the main map window This is a vector layer that is currently enabled for editing 3 4 4 The QGIS 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 sh
56. he same as would be used to open a telnet connection or ping the host 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 password used with Username to connect to the database Once the parameters have been filled in you can test the connection by clicking on the Test Connection button To save the password with the connection information check the Save Password option Tip 5 QGIS USER SETTINGS AND SECURITY Your customized settings for QGIS are stored based on the operating system On Linux Unix the settings are stored in your home directory in qt qgisrc On Windows the settings are stored in the registry Depending on your computing environment storing passwords in your QGIS settings may be a security risk 4 2 2 Loading a PostGIS Layer 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 4 2 5 for a discussion on importing data into the database To load a layer from PostGIS perform the following steps If the PostGIS layer dialog is not already open click on the Add a PostGIS Layer toolbar button Choose the connection from the drop down list and click Connect Find the layer you wish to add in the list of available layers Pee E TE Select it by clicking on it
57. his section has the sole purpose of protecting the integrity of the free software distribution 56 QGIS User Guide Version 0 7 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 copyrighted interfaces the original copyright 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
58. icense 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 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 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 th
59. ifting 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 3 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 it forward away from you to zoom in and backwards towards you to zoom out 3 4 5 The QGIS 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 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 choosing Toggle in Overview You can also add or remove all layers to the overview using the Add to Overview tool on the toolbar 3 4 6 The QGIS map 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 The status bar also shows 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
60. in a text editor and find the Plugins section Set all the plugin values to false to prevent them from loading For example to prevent the Delimited text plugin from loading the entry in qgisrc 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 Manger to determine which is causing the problem 40 QGIS User Guide Version 0 7 Figure 9 1 Plugin Manager Gas Fun Manger Mugin Directory ma meaigsnennanigg ish hrc flib qgis Te load a plugin click the checkbox next to the plugin and click Ok Name Veron Description e O Add Delimited Text Layer Version 0 1 This plugin provides support for delimi O Copyrightlabel Version 0 1 This plugin overlays copyright Informa O GPs Tools Version 0 1 Tools for loading and imparting GPS d O GRASS 0 1 GRASS layer O Graticule Creator Verlon 0 14 graticule building plugin O NorthArrow Version 0 1 Ths plugin displays a north arrow ove Postgres5QL Geoprocesing Version 0 1 Geoprocesing functions for working w O scaleBar Wesion 0 1 Plugin to draw scale baron map Version 0 1 Shape le to PostgreSQL PostGlS impor ball dl 9 1 3 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 OGR library Appendix A 1 A Data Provider plugin extends
61. indows it s COM1 or COM2 When you click OK the data will be downloaded from the device and appear as a layer in QGIS 44 QGIS User Guide Version 0 7 Figure 9 5 The download tool GPS Tools ij x Load GPX file Import other file Description This tod 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 isnt listed or if you want to change some settings you can also edit the devices This tool uses the progam GPS Babel http qosbabel sf net to transfer the data If you don t have GPS Babel installed where QGIS can find it this tool will mot work a fre uma E Edit devices Feature type Waypoints as Output file sn Layer name 9 2 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 tool Upload to GPS The layer must be a GPX layer To do this you simply select the layer that you want to upload the type of your GPS device and the port that it s 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 together with the vector editing capabilities of QGIS You can load a map create some waypoints and routes and then upload them and use them in your GPS device
62. ings 35 table editing 35 topology 33 vector data model 33 indexes see spatial index installation 6 layer context menu 8 visibility 8 layers 70 initial visibility 11 raster see rasters vector see vector layers legend 8 license exception 58 GPL 54 main window 7 map overview 9 view 9 menus 8 ogr 12 supported formats 52 plugins 40 copyright 42 core 41 delimited text 42 geoprocessing 42 gps 42 graticule 42 installing 40 manager 40 managing 40 north arrow 42 scalebar 42 SPIT 42 types 40 user contributed 40 plugins settings 41 PostGIS 12 28 layers 14 PostgreSQL connection 14 testing 15 connection manager 15 connection parameters 15 database 15 host 15 importing data see SPIT layer definition see query builder layer details 17 loading layers 14 15 password 15 port 15 query builder 16 username 15 QGIS User Guide Version 0 7 Projections custom 30 enabling 29 specifying 30 working with 28 query builder 16 adding fields 16 changing layer definitions 16 generating sample list 16 getting all values 16 testing queries 16 rasters building pyramids 27 context menu 25 formats 24 georeferenced 24 implementation 24 inverting the color map 26 loading 24 metadata 26 properties 25 26 renderers 26 standard deviation 26 statistics 27 supported formats 52 supported forms 26 transparency 26 rendering 9 halting
63. ion of 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 un derstood 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 distances between geographic locations the amount of area e g square metres 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 DAA O ES and so on These may seem simplistic but can be applied in all sorts of ways across many disciplines The results of analysis may be shown on a map but are often tabulated into a report to support management decisions The recent phenomena of location based services promise
64. isting line and click on new position Split line split an existing line to 2 parts Delete line delete existing line confirm selected line by another click Edit attributes edit attributes of existing element note that one element can represent more fea tures see above Mug close digitizing session 7 4 2 Category Tab This tab allows you to set the way in which the category will be assigned to each new feature and or assign a category to a feature e Mode what category should be attached to geometry Next not used next category not yet used in vector Manual entry define the category in Category entry No category digitize geometry without category e Category a number ID attached to digitized feature e Field feature attribute table identification 34 QGIS User Guide Version 0 7 7 4 3 Settings Tab This tab allow you to set the snapping in screen pixels This is the threshold in pixels in which new points or line ends are snapped to existing nodes This helps prevent gaps or dangles between boundaries 7 4 4 Symbology Tab This tab allows you to view and set symbology for various geometry types and their topological status e g closed opened boundary 7 4 5 Table This tab provides the means to view create or modify the database table for a given field Tip 13 GRASS EDIT PERMISSIONS You must be the owner of the GRASS mapset you want to edit
65. l config using the with gdal option For example configure with gdal usr mystuff bin gdal config 67 QGIS User Guide Version 0 7 PostgreSQL If the pg_config script is in the PATH configure will automatically detect and configure PostgreSQL support If not you can use the with pg option to specify the full path to pg_config For example configure with pg usr local psql bin pg_config GRASS To build QGIS with GRASS support you must specify the full path to the installed GRASS binary package configure with grass usr local grass 6 0 0 This assumes that GRASS is installed in the default location Change the path to match the location of your GRASS installation Example Use of Configure An example of use of configure for building QGIS with all options configure prefix usr local qgis with gdal usr local gdal bin gdal config with pg usr local psql bin pg_config with grass usr local grass 6 0 0 This will configure QGIS to use GDAL GRASS and PostgreSQL QGIS will be installed in usr local qgis If QTDIR is set and gdal config and pg_config are both in the PATH there is no need to use the with gdal and with pg options The configure script will properly detect and configure GDAL and PostgreSQL You must still use the with grass option if building with GRASS support Compiling and Installing QGIS Once properly configured simply issue the following commands make make inst
66. log Open an OGR Supported Vector Layer Look in E Mmome gsherman qgis_data from_grass e amp ex lu sE a i 3 lakes2_from_grass shp lakes2_poly shp lakes2_poly2 shp File type ESRI Shapefiles shp SHP Cancel Encoding ISO 6659 1 Improving Performance To improve the performance of drawing a shapefile you can create a spatial index A spatial index will improve the draw speed when zooming and panning Use these steps to create the index 1 Load a shapefile 2 Open the Layer Properties dialog by double clicking on the shapefile name in the legend or by right clicking and choosing Properties from the popup menu 3 Click the Create button on the Spatial Index panel 4 1 2 Loading a Maplnfo Layer To load a MapInfo layer click on the Add a vector layer toolbar bar button and change the file type filter to MapInfo mif tab MIF TAB and select the layer you want to load 4 1 3 Loading an ArcInfo Coverage Loading an an ArcInfo coverage is done using the same method as with a shapefiles and MapInfo layers Click on the Add a vector layer toolbar button to open the layer dialog Navigate to the coverage directory and select one of the following files if present in your coverage 1 lab to load a label layer polygon labels or standing points 2 cnt to load a polygon centroid layer 3 arc to load an arc line layer 13 QGIS User Guide Version 0 7 Figure 4 2 QG
67. m 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 CHAPTER 3 Getting Started This chapter gives you a quick overview of running QGIS and examining data available on the QGIS web page 3 1 Installation Installation of QGIS is documented in Appendix C The Installation Guide is distributed with the QGIS source code and is also available at http qgis org Under Windows and Mac OS X QGIS is available as a standard installer package Packages for many flavors of Linux are also available 3 2 Sample Data If you do not have any GIS data handy you can obtain a dataset for Alaska from the QGIS web site at http qgis org The Alaska data set will be used as the basis for many of the examples and screenshots provided in this document 3 3 Starting QGIS 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 a
68. mpile QGIS You may already have Qt on your system If so check to see if you have version 3 2 1 or later You can check the Qt version using the find command 65 QGIS User Guide Version 0 7 find name qglobal h 2 gt dev null xargs grep QT_VERSION_STR If you have the locate utility installed you can do the same more quickly using locate qglobal h xargs grep QT_VERSION_STR In either case the result should look something like this define QT_VERSION_STR 3 3 1 In the example above Qt 3 3 1 is installed If Qt is not installed you will have to install the Qt development package for your distribution If you are not able to install the required Qt packages you will have to build from source To install Qt from source 1 Download Qt from http www trolltech com developer choose the Qt X11 Free Edition 2 Unpack the distribution 3 Follow directions provided in the distribution directory doc html install x11 html 4 Use whatever configure options you like but make sure you include thread for use with QGIS You can configure Qt with minimal options configure thread 5 Complete the installation per the instructions provided in the Qt documentation see step 3 NOTE QGIS will not compile under Qt 4 0 x The best choice for compiling QGIS is Qt 3 3 x C 11 Building QGIS After you have installed the required libraries you are ready to build QGIS Download and untar the QGIS distribution and change
69. n After chancina a dalimatar_nrace the narco bo a Delimited text fil ass elimited text file Layer name Delimiter E Help Parse Add Layer Close to tab using t this is a regular expression for the tab character After changing the delimiter click Parse The drop down boxes now contain the fields properly parsed as shown in Figure 9 9 Choose the X and Y fields from the drop down boxes and enter a Layer name as shown in Figure 9 10 To add the layer to the map click Add Layer The delimited text file now behaves as any other map layer in QGIS Figure 9 11 48 QGIS User Guide Version 0 7 Edt Go Toots eros Heo Figure 9 8 File Selected Greate a Layer from a Delimited Text File Delimited Text Layer Description Select the file containing delimited text with lat lon coordinates that you would like to use as a point layer and this plugin will do the job for you Use the layer name box to specify the legend name for the new layer Use the delimeter box to specify what the delimeter is for your file e g space commar Delimited text file vgnis_no_east_hemi_tabbed bd o Layer name Delimiter A Eg Help Parse J Add Layer Close ely Ab Figure 9 9 Fields Parsed from Text File Be Est Go Tow genres Hew Greate a Layer from a Delimited Text File Delimited Text Layer
70. n 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 of 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 L
71. ocessing capabilities of home PC s and open source software 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 additional 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 metres 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 values of certain wavelengths of li
72. or GRASS support skip to the section on Installing GDAL OGR C 2 Getting QGIS QGIS is available in both source and package format from http qgis org In addition packages for many Linux distributions are independently maintained in various locations See the Download section on http qgis org for the latest information on package locations Packages for most of the software libraries discussed below can be found for almost all Linux distributions While it is possible to mix compiling from source and installing packages to meet the requirements for QGIS sometimes this becomes tricky Following the steps below will generally ensure a successful installation If you are using SuSE 9 1 the LinGIS distribution ftp ftp lingis org is a good choice for installing QGIS and its dependencies For information on installing dependencies and building QGIS on FreeBSD see Building QGIS on FreeBSD on http community qgis org C 3 PostgreSQL QGIS uses the latest features of PostgreSQL For this reason version 8 0 x or higher is recommended with QGIS version 0 7 If you choose to add PostgreSQL you must also install PostGIS see below 1 Download PostgreSQL source from www postgresql org 2 Extract the source 60 QGIS User Guide Version 0 7 tar xzf postgresql 8 0 1 tar gz 3 Change to the source directory cd postgresql 8 0 1 4 Configure PostgreSQL configure prefix usr local pgsql 5 Build make 6 Install
73. osing No at this point will cause them to be discarded 21 QGIS User Guide Version 0 7 Figure 4 5 Vector Digitizing Attributes Capture Dialog Quantum G On POC Seamus File View Layer Settings Plugins Help Enter Attribute Values Jigs 43D A sete a 36564980 1131 5 22 1 x Render 4 5 2 Creating a New Layer To create a new layer for editing choose New Vector Layer from the Layer menu The New Vector Layer dialog will be displayed as shown in Figure 4 6 Choose the type of layer point line or polygon To complete the creation of the new layer add the desired attributes by clicking on the Add button and specifying a name and type for the attribute Only real integer and string attributes are supported Once you are happy with the attributes click Ok 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 4 5 1 above 22 QGIS User Guide Version 0 7 Figure 4 6 Creating a New Vector Dialog New Vector Layer Type e Point Line Polygon Attributes Note that QGIS does not yet support creation of 2 5D features i e features with X Y Z 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 23
74. played 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 5 4 2 General Tab The General 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 5 4 3 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 26 QGIS User Guide Version 0 7 Tip 9 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 QGIS examines your data 5 4 4 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 depending on the level of zoom You must have write access in the directory wher
75. pplication link or shortcut on the desktop Under MS Windows start QGIS using the Start menu shortcut and under Mac OS X double click the icon in your Applications folder 3 3 1 Command Line Options QGIS supports a number of options when started from the command line To get a list of the options enter qgis help on the command line The usage statement for QGIS is Usage home gsherman qgisO7_rc bin 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 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 QGIS User Guide Version 0 7 and others supported by GDAL 2 Vectors Supported formats include ESRI Shapefiles and others supported by OGR and PostgreSQL layers using the PostGIS extension Tip 1 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 your data directory you could start QGIS with two shapefiles and a raster file set to load on startup using the following command gqgis ak_shade tif alaska shp majrivers shp 3 4 The QGIS Main Window When QGIS starts you are presented with the main window as shown below the numbers 1 through 6 in blue ov
76. re 9 3 Use the browse button to 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 OK 42 QGIS User Guide Version 0 7 Figure 9 3 The GPS Tools dialog window x GPS Tools imperio file Download from GPS Upload to GPS Description 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 9 23 GPSBabel Since QGIS uses GPX files 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 GPS device QGIS uses GPSBabel to do these things so it is recommended that you install it However 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 9 2 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 which feature type you want to import from it where you want to store the converted GPX file and
77. ributed plugins 9 1 1 Finding and Installing a Plugin When you install QGIS all of the core plugins are included these are described below Additional user contributed plugins may be available on the QGIS Community site To see what user contributed plugins are available see the plugins page on the Community site http community qgis org plugins Typically user contributed plugins are distributed in source form and require compiling For instructions on building and installing a user contributed plugin see the documentation included with the plugin 9 1 2 Managing Plugins Managing plugins consists of loading or unloading them from QGIS Loaded plugins are remembered when you exit the application and restored the next time you run QGIS To manage plugins open the Plugin Manager from the Tools menu The Plugin Manager displays all the available plugins and their status loaded or unloaded Figure 9 1 shows the Plugin Manager dialog Typically all QGIS plugins are installed in the same location This location is shown in the Plugin Directory text field You can tell QGIS to load plugins from another location by specifying a different directory Tip 14 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 qt qgisrc file in your home directory on Linux Unix Windows users will have to edit the registry On Linux Unix open the qgisrc file
78. rint button in the toolbar or choose Print from the File menu 8 1 Using Map Composer To use the map composer first add the layers you want to print to QGIS The layes should be rendered and symbolized to your liking prior to composing the map Opening the map composer provides you with a blank canvas to which you can add the current map view legend scalebar and text Figure 8 1 shows the initial view of the map composer before any elements are added The map composer has two tabs General and Item The General tab allows you to set the paper size orientation and resolution for the map The Item tab displays the properties for the currently selected map element By selecting an element on the map eg legend scalebar text etc and clicking on the Item tab you can customize the settings You can add multiple elements to the composer This allows you to have more than one map view and legend in the composer Each element has its own properties and in the case of the map its own extent 8 1 1 Adding a Map to the Composer To add the QGIS map canvas to the map composer click on the Add a new map button in toolbar Drag a rectangle on the composer canvas to add the map You can resize the map later by clicking on the Select move item button clicking on the map and dragging one of the handles in the corner of the map With the map selected you can also resize the map by specifying the width and height on the Item properties tab
79. roject Properties dialog and add additional layers to the map If you have already added layers and want to enable OTF projection open the Project Properties dialog and find the projection or geographic coordinate system you want to use in the list of projections Alternatively you can use the search feature as described in the previous section 6 3 Custom Projections If QGIS doesn t have the projection you need you can define a custom projection To define a projection se lect Custom Projections from the Settings menu Custom projections are stored in your QGIS user database In addition to your projections this database contains your spatial bookmarks and other custom data At version 0 7 of QGIS defining a custom projection requires a good understanding of the Proj 4 projection library To begin refer to Cartographic Projection Procedures for the UNIX EnvironmentNA UserOs Manual by Gerald I Evenden U S Geological Survey Open File Report 90 284 1990 available at ftp ftp remotesensing org proj new_docs 0F90 284 pdf This manual describes the use of the proj and related command line utilities The cartographic parameters used with proj and described in the user manual are the same as those used by QGIS The Custom Projections dialog requires only two parameters to define a user projection 1 a descriptive name and 2 the cartographic parameters To create a new projection click the New button and enter a descriptive name and th
80. s 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 it s 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 focused hardware and software is nothing new Global positioning system GPS receivers are becoming 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 lThis chapter is by Tyler Mitchell http www oreillynet com pub wlg 7053 and used under the Creative Commons License Tyler is the author of Web Mapping Illustrated published by O Reilly 2005 QGIS User Guide Version 0 7 What is new is how the latest hardware and software is being applied and who is applying it Traditional users of mapping and analysis tools were highly trained GIS Analysts or digital mapping technicians trained to use CAD like tools Now the pr
81. se 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 Program 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 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 t
82. shp lakes_new psql gis_data This creates a new layer named lakes_new in the the gis data database The new layer will have a spatial reference identifier SRID of 2964 See Chapter 6 for more information on spatial reference systems and projections 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 Tools menu and load the plugin by checking the box next to the SPIT plugin and click Ok 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 dialog You can add one or more files to the queue by clicking on the Add button To process the files click on the Import button The progress of the import as well as any errors warnings will be displayed as each shapefile is processed Tip 8 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 17 QGIS User Guide Version 0 7 4 2 6 Improving Performance Retrieving features from a PostgreS
83. ska Albers meters NAD27 Alaska Albers NAD83 BC Albers Cassini p gt Lambert Azimuthal Equal Area Spatial Reference Id proj longlat ellps WGS84 datum WGS84 no_defs Search gh Postgis SRID EPSG ID 1 Enable projections this checkbox is used to enable or disable OTF projection When off no projection takes place and 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 system of the map canvas 2 Projections this is a list of all projection supported by QGIS including Geographic Projected and Custom coordinate systems To use a coordinate system select it from the list by expanding the appropriate node and selecting the projection 3 Proj4 text this is the projection string used by the Proj4 projection engine This text is read only and provided for informational purposes 4 Search if you know the PostGIS or EPSG identifier for a projection you can use the search feature to find it Enter the identifier and click on Find 29 QGIS User Guide Version 0 7 6 2 1 Specifying a Projection QGIS automatically sets the map projection to the coordinate system of the first layer loaded One way to specify the map projection is to first load a layer with the projection you want for the entire map Then open the Project Properties dialog and click on the Enable on the fly projection checkbox You can now close the P
84. t 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 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 54 QGIS User Guide Version 0 7 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 translated 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 pro vided that you conspicuously and appropriately publish o
85. the SQL on the General tab or by invoking the query builder dialog on the General tab To access the properties dialog double click on a layer in the legend or right click on the layer and select Properties from the popup menu 1GiST index information is taken from the PostGIS documentation available at http postgis refractions net 18 QGIS User Guide Version 0 7 4 3 1 Vector Symbology QGIS supports a number of symbology renderers to control how vector features are displayed Currently 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 values of a particular field Continuous colour objects within the layer are displayed with a spread of colours classified by the numerical values within a specified field Unique value objects are classified by the unique values within a specified field with each value having a different symbol For layers containing point features additional renderers are available that use SVG icons Single marker a single specified icon is used for every point within the layer Graduated marker points within the layer are displayed with different icons classified by values within a particular field Unique value marker points are classified by unique values within a specified field with each value having a different icon To change
86. to a GIS program that is free of cost and can be freely modified You should have received a full copy of the license with your copy of QGIS and is also available as Appendix B Note The latest version of this document can always be found at http qgis sourceforge net docs userguide html 1 1 Major Features QGIS has many common GIS features and functions The major features are listed below 1 Support for spatially enabled PostgreSQL tables using PostGIS Support for ESRI shapefiles and other vector formats support by the OGR library including MapInfo files GRASS integration including view edit and analysis N On the fly projection of vector layers Map composer Identify features Display attribute table Select features Oo OND oF WwW Label features 10 Persistent selections 11 Save and restore projects 12 Support for raster formats supported by the GDAL library 13 Change vector symbology single graduated unique value and continuous 14 SVG markers symbology single unique value and graduated QGIS User Guide Version 0 7 15 16 17 18 19 20 1 2 Display raster data such as digital elevation models aerial photography or landsat imagery Change raster symbology grayscale pseudocolor and multiband RGB Export to Mapserver map file Digitizing support Map overview Plugins Whats New in 0 7 Version 0 7 brings several important features including projection support
87. ts of a minimum of three files 1 shp file containing the feature geometries 2 dbf file containing the attributes in dBase format 3 shx index file The technical specification for the shapefile format can be found at http www esri com library whitepapers pdfs shapefile pdf 4 1 1 Loading a Shapefile lt To load a shapefile start QGIS and click on the Add a vector layer toolbar bar button This same tool can be used to load any of the formats supported by the OGR library Clicking on the tool brings up a standard open file dialog Figure 4 1 which allows you to navigate the file system and load a shapefile or other supported data source You can also select the Encoding type for the shapefile if desired Selecting a shapefile from the list and clicking Ok loads it into QGIS Figure 4 2 shows QGIS after loading the country shp file Tip 4 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 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 by right clicking on the name in the legend and choosing Properties from the popup menu See Section 4 3 1 for more information on setting symbology of vector layers 12 QGIS User Guide Version 0 7 Figure 4 1 Open OGR Data Source Dia
88. u 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 7 4 for details 4 5 1 Editing an Existing Layer If you wish to edit an existing layer choose Start Editing from the context menu after right clicking on the legend entry for that layer Remember to backup your data before starting Once the layer is in edit mode de you will see a small icon to remind you Now that the layer is editable you can use the Capture Points icon or similar icon for line and polygon layers on the toolbar to put the QGIS cursor into digitising mode Tf you are capturing a point feature simply use the pan and zoom tools to navigate to the area of interest then click the Capture Points tool and click on the map area to create the new point feature A window will appear allowing you to set the attributes Figure 4 5 shows setting attributes for a fictitious new city in the Antarctic In its current implementation the attributes dialog box does not check that the data matches the type expected so make sure of this before pressing Ok To delete a feature select it using the selection tool and choose Delete selection from the editing tools Once you have finished adding features choose Stop Editing from the layer s context menu Choosing Yes will save the changes to disk while cho
89. understand any QGIS messages and give you direction on changing the PostgreSQL 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 have a column with a unique constraint on it QGIS additionally requires that this column be of type int4 an integer of size 4 bytes If a table lacks these items the oid column will be used instead Performance will be improved if the column is indexed note than primary keys are automatically indexed in PostgreSQL If the PostgreSQL layer is a view the same requirements exist 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 table column that is suitable If one 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 4 2 5 Importing Data into PostgreSQL Data can be imported into PostgreSQL using a number of methods PostGIS 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 into a PostgreSQL database named gis_data use the following command shp2pgsql s 2964 lakes
90. what the name of the new layer should be When you select the file to import you must also select the format of that file by using the menu in the file selection dialog see figure 9 4 All formats do not support all three feature types so for many formats you will only be able to choose between one or two types 9 2 5 Downloading GPS data from a device QGIS can use GPSBabel to download data from a GPS device directly into vector layers For this you use the tool Download from GPS see Figure 9 5 where you select your type of GPS device the port that it is connected to 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 43 QGIS User Guide Version 0 7 Figure File selection dialog for the import tool Select file and format to import CoPilot Right Planner DNA Delorme GPS Log Delorme Routes EasyGPS Binary Format Fugawi GPS Drive GPS Lil i GPSman the device Tf none of the device types works with your GPS device you can create a new type see section 9 2 7 The port is 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 On Linux this is something like dev ttySO or dev ttyS1 and on W
91. 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 which 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 i
92. you must build GRASS prior to proceeding Follow the directions on the GRASS website carefully to build version 6 0 x Additional information and the build instructions can be found at http grass itc it 63 QGIS User Guide Version 0 7 The GRASS software is available for download at http grass itc it download html C 7 Proj4 Proj4 provides the functions needed for on the fly projection of map layers in version 0 7 To build and install Proj4 download the latest version from http proj maptools org untar the distribution and configure make make install C 8 SQLite Sqlite is used to manage the projections database and store persistent data such as spatial bookmarks Download the latest 3 x version of SQLite from http www sqlite org Untar the distribution and configure make make install Note SQLite 3 x is included on Mac OS X 10 4 C 9 GDAL OGR The GDAL and OGR libraries provide support for raster and vector data formats QGIS makes use of both of these libraries which come bundled in one distribution Note A Linux binary of GDAL is available at http www remotesensing org gdal If you choose to install the binary you will also need to download and unpack the source tree since QGIS needs the header files in order to compile To install GDAL OGR from source 1 Download the GDAL distribution from http www remotesensing org gdal You should use the latest version of GDAL if possible
Download Pdf Manuals
Related Search
Related Contents
トマトガード Philips AC mains plug HQ1007 Philips Lumea IPL hair removal system SC2003/11 Samsung SH18AS0 Εγχειρίδιο χρήσης User Manual F8GFPC100ea Englisch Tools and data description manual Web application URBAN SMS suite _入札説明書 opladen & verbinden met een computer muziek Copyright © All rights reserved.
Failed to retrieve file