ETG_CostDistanceRaster

Cost Distance - Costs from Raster

Calculates for each cell of the output raster the least cost to reach one of the sources of the input feature class. The cost is calculated as distance from the cell to the source multiplied by the weight of the cells of the cost raster. The NODATA values in the cost raster are considered prohibitive cost.

The performance of the function depends very much on the difference between the smallest and largest weights. The larger this difference is, the slower the function will be.

Inputs:

Input feature dataset - Sources (Point, Polyline, Polygon)
Output raster name and format
A Cost raster - full name to the cost raster.
Cutoff cost - cells with larger than this cost (distance x weight) to reach will not be allocated to any source.

Outputs:

A floating point raster. Each cell will have as a value the minimum cost to be reached from one of the sources.
- The extent of the output is equal to the extent of the input cost raster.
- The cell size of the output is equal to the cell size of the input cost raster.

Example:

Source points. Cost Raster - Slope raster of digital terrain model used in the example.

The result of the Cost Distance function.

The result of the Cost Distance function over the zones derived with the Cost Allocation function.

Notes:

The output Cost Distance raster will have the spatial reference of the input Cost raster dataset.
The Cost raster can not have cells with negative or zero values - the cost can not be 0 or negative.
Cell locations with NoData in the Cost raster act as barriers.
The input format accepted are file based rasters - ERDAS IMAGINE or Tagged Image File Format (TIFF).
The .NET ToolBox for ArcGIS Desktop accepts also FileGDB Raster inputs.
For file based rasters initially the name of the output raster define the raster format:
- .img extension (for example raster1.img) - ERDAS IMAGINE image.
- .tif extension (for example raster1.tif - image.
- The initial output raster format can be changed by selecting the desired output in the dialog.

Running Programmatically

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Parameters

Expression	Explanation
Function Name	CostDistanceRaster
<InputFeatures>	A String - the full path to the input feature dataset.
<output raster>	A String - the full name of the output raster.
<CostRaster>	A String representing the cost raster dataset.
<CutOff>	A Double representing the cut off cost - the value of the cells with larger than this cost (distance x weight) to reach will be set to NODATA.

Running the function

ETSPath used in the table below is the full path to ETSRun.exe (E.G. "C:\Program Files\ETSpatial Techniques\ETSurface\ETSRun.exe")

CostRaster

Language	Syntax
Python	subprocess.call([ETSPath, "CostDistanceRaster", "InputFeatures", "output raster", "CostRaster", "CutOff"])
.NET using ETSRun.exe	StartInfo.FileName = ETSPath StartInfo.Arguments = "CostDistanceRaster" "InputFeatures" "output raster" "CostRaster" "CutOff"
.NET using ETSOutX.dll	CostDistanceRaster(InputFeatures, output raster, CostRaster, CutOff)
ArcPy	arcpy.CostDistanceRaster("InputFeatures", "output raster", "CostRaster", "CutOff")

Notes:

<> - required parameter
{} - optional parameter
See examples for Python , .NET or ArcPy
The argument separator for StartInfo.Arguments is space. If a string might contain a space, you need to double quote it.

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