Point Statistics (Spatial Analyst)
Summary
Calculates a statistic on the points in a neighborhood around each output cell.
Usage
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When the field is integer, the available overlay statistic choices are Mean, Majority, Maximum, Median, Minimum, Minority, Range, STD, Sum, and Variety. When the field is floating point, the only allowed statistics are Mean, Maximum, Minimum, Range, STD, and Sum.
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For statistic types Majority, Maximum, Median, Minimum, Minority, Range, and Sum, the output data type of the raster will be the same as the input field type. For statistic types Mean and STD, the output raster will always be floating point. For Variety, the output raster will always be integer.
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If there aren't any points in the neighborhood of a raster cell, the Variety statistic assigns it a value of 0. For the other statistics, NoData is assigned.
Syntax
| Parameter | Explanation | Data Type |
in_point_features |
The input point features for which to calculate the statistics in a neighborhood around each output cell. The input can be either a point or multipoint feature class. | Feature Layer |
field |
Field can be any numeric field of the input point features. It can be the Shape field if the input features contain z. | Field |
cell_size (Optional) |
Cell size for output raster dataset. This is the value in the environment if specifically set. If not set in the environment, it is the shorter of the width or height of the extent of the input feature dataset, in the output spatial reference, divided by 250. | Analysis Cell Size |
neighborhood (Optional) |
The Neighborhood class dictates the shape of the area around each input point used to calculate the statistic. The different types of neighborhood available are NbrAnnulus, NbrCircle, NbrRectangle, and NbrWedge. The following are the forms of the neighborhoods:
The {CELL | MAP} parameter defines the distance units as either being Cell units or Map units. The default neighborhood is a square NbrRectangle with a width and height of 3 cells. | Neighborhood |
statistics_type (Optional) |
The statistic type to be calculated. The calculation is performed on the values of the specified field of the point input in the neighborhood of each output raster cell.
| String |
Return Value
| Name | Explanation | Data Type |
| out_raster |
The output point statistics raster. | Raster |
Code Sample
This example determines a statistic (the sum) on the input shapefile point features that fall in a circular neighborhood around each output raster cell.
import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outPointStats = PointStatistics("ca_ozone_pts.shp", "OZONE", 500,
NbrCircle(10000, "MAP"), "SUM")
outPointStats.save("C:/sapyexamples/output/pointstatsout")
This example determines a statistic (the average) on the input shapefile point features that fall in a circular neighborhood around each output raster cell.
# Name: PointStatistics_Ex_02.py
# Description: Calculates a statistic on points over a specified
# neighborhood outputting a raster.
# Requirements: Spatial Analyst Extension
# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *
# Set environment settings
env.workspace = "C:/sapyexamples/data"
# Set local variables
inPointFeatures = "ca_ozone_pts.shp"
field = "OZONE"
cellSize = 500
neighborhood = NbrCircle(6000, "MAP")
# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")
# Execute PointStatistics
outPointStatistics = PointStatistics(inPointFeatures, field, cellSize,
neighborhood, "MEAN")
# Save the output
outPointStatistics.save("C:/sapyexamples/output/pointstatout")