This tool can be used to identify the 'catchment area' of each source grid cell in a cost-distance analysis. The user must specify the names of the input Source and Back-Link raster files. Source cells (i.e. starting points for the cost-distance or least-cost path analysis) are designated as all positive, non-zero valued grid cells in the Source raster. A Back-Link raster file can be created using the Cost-Accumulation tool and is conceptually similar to the D8 flow-direction pointer raster grid in that it describes the connectivity between neighbouring cells on the accumulated cost surface.
NoData values in the input Back-Link image are assigned NoData values in the output image. The output raster is of the integer data type and categorical data scale.
The following is an example of a Python script that uses this tool:
wd = pluginHost.getWorkingDirectory()
sourceFile = wd + "source.dep"
backLinkFile = wd + "back link.dep"
outputFile = wd + "output.dep"
args = [sourceFile, backLinkFile, outputFile]
pluginHost.runPlugin("CostAllocation", args, False)
This is a Groovy script also using this tool:
def wd = pluginHost.getWorkingDirectory()
def sourceFile = wd + "source.dep"
def backLinkFile = wd + "back link.dep"
def outputFile = wd + "output.dep"
String args = [sourceFile, backLinkFile, outputFile]
pluginHost.runPlugin("CostAllocation", args, false)