Here - Rutgers Center on Public Security
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1. Information behavior environmental incident Known risks Risk Terrain Modeling resources emerge 7 i Utility perans moO yr User Manual vuinerapiiities 2 sin alala li i A ppendix Recommended Citation Caplan J M Kennedy L W amp Piza E L 2013 Risk Terrain Modeling Diagnostics Utility User Manual Appendix Rev 1 Newark NJ Rutgers Center on Public Security i Available at www rutgerscps org software Updated 2 6 15 Rev 8 Appendix A Multipart polygon shapefiles To combine existing features to make a multipart feature in ArcMap use either the Merge or Union tools Merge allows you to combine features within the same layer while Union works with features in different layers Appendix B Use NN analysis to strategically select Density or Proximity Want to reduce run time by purposefully selecting Density or Proximity for each risk factor i e instead of Both Then consider running a Nearest Neighbor NN Analysis on each risk factor s points prior to inputting them into the RTMDx Utility Set the RTMDx Operationalization to Proximity if the points are not significantly clustered or if the Observed Mean Distance OMD of the point features is greater than the Max Spatial Influence distance that you will set e g 4 blocks Set the Operationalization to Density if the points are significantly clustered and or if they have an OMD les2. Figure 2 Importing the model into ArcMap Double click on the RTMDx_Poly_ Points tool to open Load the polygon shapefile into the first text box by clicking the folder icon and navigate to the shapefile on your computer In ArcMap dragging the layer from the table of contents to this text box is not supported In the next two text fields enter the desired spatial influence distance in feet for this risk layer This value should match the spatial influence specified in the RTMDx Utility so that it is consistent with the other risk factors For example if the average block length of your study area is 500 feet and the spatial influence was set to half a block in RTMDx then 250 feet should be entered into this model In the text field titled SAVE THE POINT LAYER specify a name and save location for the new points file by clicking the folder icon By default layers are saved with the name PTS FROM_POLY_FINAL in a newly created folder on the C drive Leaving this setting as is the first time the tool is run will not create any problems but also doing so on subsequent runs will result in an error message stating that the output layer already exists Thus it is recommended that you always select a different save folder and specify a name for the final point layer After the model runs the newly created point shapefile is added to the main map window in ArcMap LOAD POLYGON SHAPEFILE FROM HERE MANUALLY DRAGGING T
3. 9 990000e Name Property Bands 1 Pixel Depth 32 Bit Uncompressed Size 136 28 KB Extent left top right bottom 2753541 7500 1051428 5100 2798697 2210 1010419 9700 4 mW p Location C Users jcaplan Desktop RTMDxDemoData ic Compression Type Compression Quality 75 1100 About export raster data punar Appendix G Guide to RTM Step 5 when using RTMDx The product of Step 5 is to compile a comprehensive list of risk factors related to the outcome event generally Specifically however you want to include risk factors that make sense for your particular study area Here is how we have come to prepare risk terrain models for our own work at Rutgers when using the RTMDx Utility Following a review of the empirical literature and informed by practitioner insights we obtain data sets e g shapefiles of all potential risk factors These data as well as outcome event data are added to ArcMap for visual exploration First we varify that the data makes sense e g If we know there to be 5 gorcery stores within the study area boundary are there 5 point features Then by turning on and off risk factor layers one at a time on top of the outcome event layer we visually inspect the intersection or lack thereof of risk factor points and outcome event points We look for some evidence of a spatial relationship between the outcome event points clusters and each risk factor feature set We choose to include facto
4. administrative privileges firewalls or other restrictions that could prevent downloads or installations of the R libraries this problem could arise Try uninstalling the RTMDx Utility and uninstall R and then reinstall the RTMDx Utiliy with administrative permissions on the computer Appendix P The model ran successfully but no HTML report will display This could occur when the file name of one of the model s output files is longer than 164 characters including the path name The Windows OS cannot save files that are longer than 164 characters So in essence files created by the RTMDx Utility that are longer than this are not saved and are lost Solution shorten the file name and or file path and re run the model
5. and 2 cells with a risk value of 698 So there are 10 cells that were outliers The rest of the 21 302 cells were within the 1 298 risk value range This is likely what you are experiencing as well Appendix K American Decimals and European Commas If the RTMDx Utility runs but fails to build GeoTiffs or if the Relative Risk Values just don t seem correct it may be due to the language package you are using in Windows A CSV file produced by the RTMDx Utility is generated by the R script which then gets written as a GeoTiff American English uses periods as decimal points e g 100 01 while European and some other languages use commas e g 100 01 The Utility was coded using American English and requires the American English version of R If you are experiencing trouble with the Utility s output consider switching the Window s language from your native language to English Then uninstall R GDAL and the RTMDx Utility from your computer Install the English version of R and then reinstall the RTMDx Utility Appendix L Firewall permissions installation failed It is likely that any dependencies are downloaded via HTTP port 80 This is probably already open but only to whitelisted URLs Hopefully adding the below URLs to your firewall s permissions should allow installation The GDAL download is http download gisinternals com sdk downloads release 1600 gdal 1 9 2 mapserver 6 2 0 zip The base download directory for R
6. Projections for shapefiles and values formats for XY coordinates in CSV files must be exactly the same 2 When the software encounters multi feature polygons it chooses the first polygon If the chosen polygon includes none of the outcome events then this error will occur To solve the problem merge the multiple features into one multi part polygon Appendix E nternal data preparation The data preparation component of the RTMDx Utility forms a grid that covers the entire study area plus a buffer The processing of spatial influence occurs across this whole raster before cells are masked via the study area boundary This process is also designed to include risk factors that are outside of the study area which could influence cells within the study area Only cells that are included within the mask cells that intersect the study area boundary by at least a small amount are passed to the R script for statistical analysis Additionally as the study area polygon becomes more complex the calculation of which cells to include in the mask takes longer Resulting GeoTiffs will only include risk values for cells in the mask The mask is filtered for modeling to only include the minimum number of cells necessary to completely cover the study area polygon For instance if the polygon includes a hole the cells completely contained within the hole will not be included When the Utility completes processing and generates GeoTIFFs these GeoTIFFs only co
7. and its dependencies is http cran rstudio com Appendix M Specified argument was out of the range of valid values Parameter name X called on empty point This error is likely a projection issue Make sure that all shapefiles and or XY coordinates used are projected exactly the same way as one another and the study area boundary file Appendix N The R script couldn t find any Risk Factors that correlated with the Outcome Event Data This error means that a significant risk terrain model could not be found and that there are no factors that were inputted tested that spatially correlate with the outcome event locations Appendix O Unable to access index for repository such as the following error message within the Log tab of the RTMDx Utility Warning message In normalizePath path expand path winslash mustWork path 1 sl users DFORNWAL R win library 3 1 Access is denied Installing package into 4 sl users DFORNWAL R win library s3 1 as lib is unspecified Warning unable to access index for repository http cran rstudio com bin windows contrib 3 1 Installing package into sl users DFORNWAL R win library 3 1 as lib is unspecified This is likely caused when the Utility tries to install packages libraries for R but is unable to do so due to file permissions Several R packages should be installed automatically during the initial install process but if your computer has certain
8. HE LAYER FROM THE ARCMAP TABLE OF CONTENTS TO THIS DIALOG BOX IS NOT SUPPORTED YOU MUST CLICK THE FOLDER TO LOAD THE LAYER a RTMDx_Poly_Points NOTE THE MODEL ONLY WORKS WITH SHAPEFILES ANYTHINGIN GEODATABASE FORMAT MUST FIRST BE CONVERTED TO A SHAPEFILE Click error and warning icons for more information LOAD POLYGON LAYER VIA FOLDER ICON C Users Owner Desktop models POLYGON_LAYER shp ENTER SPATIAL INFLUENCE DISTANCE IN FEET 100 ENTER THE SPATIAL INFLUENCE DISTACNE USED BOTH OF THESE FIELDS C RTMOX_POLYTOPOINTS_OUTIPTS_FROM_POLY_FINAL shp SPECIFY A NAME AND SAVE LOCATION FOR THE NEW POINTS FILE BY DEFAULT LAYERS ARE SAVED TO A NEWLY CREATED FOLDER ON THE C DRIVE LEAVING THIS SETTING AS IS THE FIRST TIME YOU RUN THE MODEL WILL NOT CREATE ANY PROBLEMS BUT SUBSEQUENT RUNS WILL RESULT IN AN ERROR MESSAGE STATING THAT THE OUTPUT LAYER ALREADY EXISTS THUS IT S RECOMMENDED THAT YOU SELECT A DIFFERENT SAVE FOLDER Figure 3 RTMDx Polygon Conversion Tool Window 6 PolytoPoints_10 1 ArcMap File Edit View Bookmarks Insert Selection Geoprocessing Customize Windows Help 5 eb 1 2613 y Yi ae M COPiOSBIGIAGS z PTS_FROM_POLY_FINAL POLYGON ah i Figure 4 Final point shapefile and the polygon layer it was created from In conclusion there are a few things that you should keep in mind regarding this tool First it was created using ArcMap 10 1 and will not work on earlier vers
9. S or QGIS if you are worried about it Otherwise it s probably OK to ignore the error messages as the Utility will still run Appendix J The range of Relative Risk Values differ from RTMDx output when manually recreate the best model in ArcMap See page 25 of the User Manual It says something to the effect of Several types of kernel functions are used by geographic information systems GIS to produce density maps The RTMDx Utility uses the Epanechnikov kernel function which closely matches native ArcMap kernel density calculations though not exactly Tolerances for Join or Clip operations in different software or on different computers may also vary This means that manually producing density or proximity risk map layers in ArcMap or other GIS software could yield maps and relative risk scores that do not exactly match the RTMDx Utility s output The differences if any should be slight This is generally OK and should not be of any concern for most users intents and purposes 6 As an example in one of our Beta test models the Utility identified relative risk scores to cells ranging from 1 for the lowest risk cell to 298 0 for the highest risk cell for 2010 Robberies But when we used the formula in Raster Calculator it produced a relative risk score between 1 and 698 To understand the problem we converted the raster RTM map to vector and found 6 cells with a relative risk value of 326 2 cells with a risk value of 427
10. e NN Threshold So in this case it would be 1 500ft 2 3 000ft Features that are significantly clustered and whose mean observed distances are below the NN Threshold can be set to Both to let the Utlity decide which is better if both options are reasonable Appendix H Converting polygons to point features Using the RTMDx Polygon to Points Tool in ArcMap Currently the RTMDx Utility only accepts risk factors as point shapefiles Since risk factors may be represented as polygon features i e public housing complexes or parks these files must be converted to point features in order for them to be utilized within the Utility ESRI s ArcMap platform provides a number of tools that convert polygon features to points Each of these tools has its own process for the conversion meaning that parameters such as the number of points that represent the polygon and the precise location of points differ across tools Therefore to ensure that this conversion occurs in a manner that is both appropriate for Risk Terrain Modeling analysis and consistent across users researchers at the Rutgers Center on Public Security have created a ModelBuilder tool for ArcMap version 10 1 that automates the process of converting polygon features to points The tool separates the polygon layer into two separate components and then converts each of these components to a point file First the border of the polygon is converted to a point file
11. ions Second the model creates two new folders directly on your C drive for the purpose of saving the necessary temporary files The model checks to see if the folders exist before creating them so on subsequent runs the model skips the folder creation if they are already present Therefore you will need sufficient administrative privileges to write directly to the C drive in order to run the model Lastly the model only supports shapefiles Polygon layers saved in geodatabase format must first be converted into shapefiles before being utilized in the model Appendix l ERROR while trying to put something into our datatable inputs Log About Main program log Got file for Outcome events C RIMDx EVENIDATA Shootings2012 shp Error while trying to put something into our datatable row 30 Error while trying to put something into our datatable row 173 This error message was investigated during the software s development What s happening is that the shapefile inputs are being validated by a NET library that interprets geometry slightly differently than Esri So while ArcGIS might not complain about a shapefile object the validator does In the Utility the shapefile is validated on a row by row basis and when an error is produced the validation and loading continues These errors should not compromise the results significantly if there are a lot of records in the file A possible fix would be to run a shapefile cleaner in ArcGI
12. ntain values for the cells that were included in the modeling process In this example they would not include values for the cells within the hole Appendix F Convert GeoTiff to a GRID with ArcGIS From ArcMap right click on the GeoTiff in the Table of Contents gt Data gt Export Data The Export Raster Data dialog box will appear Specify a Name and Location for the new file and select GRID from the Format drop down menu Click the Save button to create a new GRID raster layer Layers output csv 1234310808 output output_score tif Value Copy High 17 165 x Remove Low 1 Joins and Relates gt Zoom To Layer 8 Zoom To Raster Resolution Visible Scale Range gt Edit Features Save As Layer File lt gt Export Data vr Export Data p aaan E i TE Export raster data from this layer Af Properties View Item Description to the format of your choice You can also choose other settings such as the extent of data the spatial reference and cell size Export Raster Data output csv 1234310808 output output_score tif Extent Spatial Reference Data Frame Current Raster Dataset Original Data Frame Current Raster Dataset Original Selected Graphics Clipping Clip Inside Output Raster Use Renderer Square Cell Size cx cy 230 3850561 230 3850561 Force RGB Raster Size columns rows 196 178 Use Colormap NoDataas
13. r Dropbox DATASETS C Users Owner Dropbox RTM_NU_EXPERIMENT Budget 7 Fayetteville a E IRB E IRB Marin Kurti s Work Models amp Tutorials Models IPIR_Toolsets PLOYGON_TO_POINTS_V2 a E sample_ploygons RTMDx_Poly_to_points_v10 1 tbx Pa converntpolytopoints 10 1 Figure 1 Opening the model in ArcCatalog ArcToolbox Add Toolbox rents ArcToolbox ee q sA Add Toolbox g Lookin 5 Home Models pLOYGON TOP amp fy 8 7 a D 9 E 3D Analyst Tools Ba ZS Envir E sample_ploygons m Analysis Tools RTMDx Poly to_points v10 1 tbx 4 Cartography Tools E 3 Conversion Tools Data Interoperability Tools amp Data Management Tools m Editing Tools E S Geocoding Tools E amp Geostatistical Analyst Tools amp p Statistics m amp Linear Referencing Tools G Cartography Tools m amp Multidimension Tools Ss Conversion Tools F S Network Analyst Tools 3 Data Interoperability Tools Nunes EEE R bo points sD m F S Data Management Tools RTMDx_Poly_to_points_v10 1 4 amp Editing Tools Show of type Toolboxes Pa converntpolytopoints_10 1 amp Geocoding Tools Geostatistical Analyst Tools H Server Tools amp Linear Referencing Tools Spatial Analyst Tools amp Multidimension Tools E Spatial Statistics Tools amp Network Analyst Tools amp Tracking Analyst Tools Add Toolbox
14. rs that appear to be visually spatially related to the outcome event locations and exclude the factors that appear otherwise If in doubt keep it Note that the RTMDx Utility can only accept up to 30 risk factor inputs After the pool of possible risk factors are selected via visual inspection within a particular study area they will have to be inputted into the RTMDx Utility for final selection by way of statistical testing One parameter that has to be set in the Utility is the Operationalizion The options are Proximity Density or Both You can reduce the Utility s run time by making this parameter choice strategically and objectively for each risk factor by setting Proximity for risk factors whose mean distance between point features is larger than the distance of the Max Spatial Influence This information can be obtained from the output of the Nearest Neighbor Analysis tool in ArcGIS Using this tool you can also set Proximity for risk factors whose features do not significantly cluster So for example if the block length is 500 and the Max Spatial Influence is set to 3 blocks in the Utility then point features that are farther than 1 500ft on average from each other are not likely to be found to have a meaningful Density spatial influence so testing for only Proximity is reasonable and will reduce the computational run time To be on the safe side we often double th
15. s than or equal to the Max Spatial Influence distance that you intend to set as a parameter in the RTMDx Utility Appendix C Why only 30 risk factors Memory issues may arise Runtime is a function of the Number of Cells the Number of Factors the Number of Analysis Bands the Number of Operationalization Types So if a model uses 15 risk factors e g 14 operationalized as Both and 1 as Proximity evaluated for 6 Analysis Bands each i e 3 Blocks Half it generates 174 variables each represented by a separate raster map This multiplied by 104 733 cells of 250ft x 250ft in a fairly large jurisdiction generates a matrix with 18 223 542 values in it In order to serialize this matrix into a CSV file for statistical analysis the computer will hold all of the raster maps 174 in memory The RTMDx Utility was developed in a way that increases the amount of memory available for this process However models can quickly get into the realm where a single computer cannot process so much data The amount of memory on a computer is going to be a limiting factor in many cases Memory usage is directly dependent on the number of Cells and the number of Variables generated For these reasons the risk factor inputs have been capped at 30 in order to limit the size of the analysis matrix and prevent errors Appendix D Error message Too few events within the study area 0 events found 1 Make sure all inputs are properly projected
16. with the user specifying the distance between the individual points Second the polygon is converted into a raster with the cell size specified by the user The raster is then converted into a point file with points representing the center of each raster cell These two separate point files are then merged into a final point layer This multi step process ensures that the entire area of the polygon both the perimeter and interior is represented in the newly created point feature shapefile The polygon to point tool can be run from within ArcCatalog or ArcMap In ArcCatalog simply navigate to the tool within the Catalog Tree and double click to open it see Figure 1 In ArcMap you first must import the model into ArcToolbox see Figure 2 Right click within the ArcToolbox window and select add toolbox Navigate to the RTMDx_Poly_to_Points_v10 1 tbx file on your computer click on the file and then click the open button The toolbox then appears within the ArcToolbox window in ArcMap Aj ArcCatalog C Users Owner Dropbe File Edit View Go Geoprocessing Customize Windows Help Gh PO x SERFS QE z C Users Owner Dropbox RTM_NIJ_EXPERIMENT Models amp Tutorials Models PLOYGON_TO_POIN 74 ime Catalog Tree A X Contents Preview Description Folder Connections 7 ICA Name Type 4 E CAUsers Owner Desktop Pa converntpolytopoints 10 1 Toolbox Tool E C Users Owner Dropbox C Users Owne
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