Extract by Circle (Spatial Analyst)

Summary

Extracts the cells of a raster based on a circle.

Usage

Syntax

ExtractByCircle (in_raster, center_point, radius, {extraction_area})
ParameterExplanationData Type
in_raster

The input raster from which cells will be extracted.

Raster Layer
center_point

The Point class dictates the center coordinate (x,y) of the circle defining the area to be extracted.

The form of the class is:

  • Point (x, y)

The coordinates are specified in the same map units as the input raster.

Point
radius

Radius of the circle defining the area to be extracted.

The radius is specified in map units and is in the same units as the input raster.

Double
extraction_area
(Optional)

Identifies whether to extract cells inside or outside the input circle.

  • INSIDE A keyword specifying that the cells inside the input circle should be selected and written to the output raster. All cells outside the circle will receive NoData values on the output raster.
  • OUTSIDE A keyword specifying that the cells outside the input circle should be selected and written to the output raster. All cells inside the circle will receive NoData values on the output raster.
String

Return Value

NameExplanationData Type
out_raster

The output raster containing the cell values extracted from the input raster.

Raster

Code Sample

ExtractByCircle example 1 (Python window)

This example extracts cells within a 500-meter radius around a point location.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outExtCircle = ExtractByCircle("elevation", arcpy.Point(482838.823, 222128.982),
                                500, "INSIDE")
outExtCircle.save("c:/sapyexamples/output/extcircle")
ExtractByCircle example 2 (stand-alone script)

This example extracts cells within a 1,000-meter radius around a point location.

# Name: ExtractByCircle_Ex_02.py
# Description: Extracts the cells of a raster based on a circle.
# Requirements: Spatial Analyst Extension
# Author: ESRI

# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *

# Set environment settings
env.workspace = "C:/sapyexamples/data"

# Set local variables
inRaster = ("elevation")
centerPoint = arcpy.Point(482838.823, 222128.982)
circRadius = 1000
extractType = "INSIDE"

# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")

# Execute ExtractByCircle
outExtCircle = ExtractByCircle(inRaster, centerPoint, circRadius, 
                               extractType)

# Save the output 
outExtCircle.save("c:/sapyexamples/output/extcircle02")

Environments

Related Topics

Licensing Information

ArcView: Requires Spatial Analyst
ArcEditor: Requires Spatial Analyst
ArcInfo: Requires Spatial Analyst

6/29/2011