Zonal Geometry (Spatial Analyst)

Summary

Calculates for each zone in a dataset the specified geometry measure (area, perimeter, thickness, or the characteristics of ellipse).

Learn more about how Zonal Geometry works

Illustration

Zonal Geometry illustration
OutRas = ZonalGeometry(InRas1,"VALUE","AREA")

Usage

Syntax

ZonalGeometry (in_zone_data, zone_field, {geometry_type}, {cell_size})
ParameterExplanationData Type
in_zone_data

Dataset that defines the zones.

The zones can be defined by an integer raster or a feature layer.

Raster Layer | Feature Layer
zone_field

Field that holds the values that define each zone.

It must be an integer field of the zone dataset.

Field
geometry_type
(Optional)

Geometry type to be calculated.

  • AREA The area for each zone.
  • PERIMETER The perimeter for each zone.
  • THICKNESS The deepest (or thickest) point within the zone from its surrounding cells.
  • CENTROID Locates the centroids of each zone.
String
cell_size
(Optional)

The processing cell size for the zonal operation.

This is the value in the environment if specifically set. If the environment is not set, the default for the cell size is determined by the type of the zone data as follows:

  • If the zone dataset is a raster, the cell size is the same as the zone raster.
  • If the zone dataset is a feature, the cell size is the shorter of the width or height of the extent of the zone feature dataset in the output spatial reference, divided by 250.

Analysis Cell Size

Return Value

NameExplanationData Type
out_raster

The output zonal geometry raster.

Raster

Code Sample

ZonalGeometry example 1 (Python window)

This example determines the area for each zone defined by the input polygon shape file.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outZonalGeometry = ZonalGeometry("zones.shp", "Classes", "AREA", 0.2)
outZonalGeometry.save("C:/sapyexamples/output/zonegeomout3")
ZonalGeometry example 2 (stand-alone script)

This example determines the area for each zone defined by the input polygon shape file.

# Name: ZonalGeometry_Ex_02.py
# Description:Calculates for each zone in a dataset the specified geometry 
#   measure (area, perimeter, thickness, or the characteristics 
#   of ellipse).
# 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
inZoneData = "zones.shp"
zoneField = "Classes"
cellSize = 0.2

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

# Execute ZonalStatistics
outZonalGeometry = ZonalGeometry(inZoneData, zoneField, "AREA", cellSize)  

# Save the output 
outZonalGeometry.save("C:/sapyexamples/output/zonegeomout2")

Environments

Related Topics

Licensing Information

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

6/29/2011