SNIP Installation Guide

This short manual helps you to install and run SNIP with ArcGIS.

System Requirements You need to have installed Python 2.7 and a running arcpy library from ArcGIS.

Remark: SNIP was tested on Python Version 2.7 and ArcGIS 10.2. In case later versions are used adaptations might be necessary.

Step 1: Download all Files

• Download all python files and the ArcToolbox from: https://github.com/eggimasv/SNIP
• Store all files in a local folder and change the path in the SNIP.py file on line 41. (e.g pythonScriptPath = "Q://yourLocalPath/../../FolderWithPythonScripts/")

Step 2: Install the ArcToolbox

Open the ArcToolbox in your ArcCatalog. Set the link in the ArcToolbox to the file SNIP.py (right click on toolbox / properties / location. Set the link to the main python file named SNIP_arcgis.py)

Step 3: Prepare GIS Data

For running SNIP the GIS data input need to contain the following properties (check with provided test dataset to compare all attributes):

Street Network (Single Part Line Shape)

• LENGTH (Length of the line segment)
• X_START (X coordinate of line segment start.)
• X_END (X coordinate of line segment end)
• Y_START (Y coordinate of line segment start)
• Y_END (Y coordinate of line segment end)

The coordinates of the segment points can e.g. be found with the “split Line at vertices” tool in ArcGIS. We recommend to generalize the street network to reduce the number of nodes.

Buildings (Point Shape)

• NEAR_X (X coordinate of nearest point on street network)
• NEAR_Y (Y coordinate of nearest point on street network)
• Q (Number of Persons living in the building)

The closest point on the street network of each node needs to be found. This can be done with a near Analysis in ArcGIS

DEM (Point Shape)

• POINT_X (X coordinate of central cell point)
• POINT_Y (Y coordinate of central cell point)
• GRID_CODE (Height)

In case a raster is provided the raster needs to be converted to points.