ETG_PointStatistics

Point Statistics

Analyses the values of a raster within user defined neighborhood around each point of the input point dataset. Calculates statistics for each point and adds them in the attribute table of the output.

Neighborhoods (the grey cell is the cell in which the point is located):

Square
- Width = 3
- Width = 5
Circle
- Diameter = 3
- Diameter = 5

Inputs:

A point feature layer
Output point feature layer
A raster dataset for which the statistics will be calculated.
A prefix for the field names. The function adds several fields to the polygon attribute table. The prefix will help the user to calculate the statistics of several rasters for the same points and add the results to the same attribute table. For example the user wants to calculate statistics for the slope and elevation for a point dataset. This requires two different rasters (Elevation and Slope). The function needs to be run twice
- on the Elevation raster with prefix "EL"
- on the Slope raster with prefix "SL"

Outputs:

A point dataset - a copy of the original points
All the original attributes will be preserved.
Depending on the type of the raster used, the following statistics will be calculated for each point and added to the attribute table of the output (XXX in the field names below replaces the prefix used in the function).
- Integer and Floating point rasters
  - XXX_Count - the number of cells within a zone
  - XXX_ZVal - the Z value of the cell in which the point is located.
  - XXX_Sum - the sum of the cell values within a zone
  - XXX_Min - the minimum values within a zone
  - XXX_Max - the maximum value within a zone
  - XXX_Range - the range of values within a zone
  - XXX_Mean - the average of the values within a zone
  - XXX_STD - the standard deviation of the values in a zone
  - XXX_Median - the median value in a zone
- Integer rasters only
  - XXX_Major - the majority value (the value that appears most timesin a zone).
  - XXX_Minor - the minority value (the value that appears least times in a zone).
  - XXX_Var - variety (the number of unique values in a zone).

Running Programmatically

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Parameters

Expression	Explanation
Function Name	PointStatistics
<InputPoints>	A String - full path to the Input Point dataset.
<OutputPoints>	A String - the full path to the output point layer.
<InputRaster>	A String - full path to the input raster dataset.
<NeighborhoodType>	A String - the neighborhood type. Valid values: Square and Circle.
<NeighborhoodSize>	An integer - the side of the square or the diameter of the circle in pixels/number of cells. This should be an odd number.
{Prefix}	A String (maximum 3 characters) representing the prefix. See description above.

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")

InputRaster

Language	Syntax
Python	subprocess.call([ETSPath, "PointStatistics", "InputPoints", "OutputPoints", "InputRaster", "NeighborhoodType", "NeighborhoodSize", "Prefix"])
.NET using ETSRun.exe	StartInfo.FileName = ETSPath StartInfo.Arguments = "PointStatistics" "InputPoints" "OutputPoints" "InputRaster" "NeighborhoodType" "NeighborhoodSize" "Prefix"
.NET using ETSOutX.dll	PointStatistics(InputPoints, OutputPoints, InputRaster, NeighborhoodType, NeighborhoodSize, Prefix)
ArcPy	arcpy.PointStatistics("InputPoints", "OutputPoints", "InputRaster", "NeighborhoodType", "NeighborhoodSize", "Prefix")

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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