ArcMap

Equal To Frequency

Available with Spatial Analyst license.

Summary

Evaluates on a cell-by-cell basis the number of times the values in a set of rasters are equal to another raster.

Illustration

Equal To Frequency illustration
OutRas = EqualToFrequency(ValRas, [InRas1, InRas2, InRas3])

Usage

  • An arbitrary number of rasters can be specified in the input rasters list.

  • When a multiband raster is specified for the Input value raster (in_value_raster in Python), only the first band will be used. To process a different band, specify the specific band to use.

  • When a multiband raster is specified as one of the Input rasters (in_rasters in Python), all the bands will be used.

    To process a selection of bands from a multiband raster, you can first create a new raster dataset composed of those particular bands with the Composite Bands tool, and use the result in the list of the Input rasters (in_rasters in Python).

  • If a cell location contains NoData on any of the input rasters, that location will be assigned NoData on the output.

  • The output raster is always of integer type.

  • See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.

Syntax

EqualToFrequency(in_value_raster, in_rasters)
ParameterExplanationData Type
in_value_raster

For each cell location in the input value raster, the number of occurrences (frequency) where a raster in the input list has an equal value is counted.

Raster Layer
in_rasters
[in_raster,...]

The list of rasters that will be compared against the value raster.

Raster Layer

Return Value

NameExplanationData Type
out_raster

The output raster.

For each cell in the output raster, the value represents the number of times that the corresponding cells in the list of rasters are the same as the value raster.

Raster

Code sample

EqualToFrequency example 1 (Python window)

This example evaluates the number of times a set of input rasters is equal to another raster and outputs the result as a TIFF raster.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outETF = EqualToFrequency("cost", ["degs", "negs", "fourgrd"])
outETF.save("C:/sapyexamples/output/outetf.tif")
EqualToFrequency example 2 (stand-alone script)

This example evaluates the number of times a set of input rasters is equal to another raster and outputs the result as a Grid raster.

# Name: EqualToFrequency_Ex_02.py
# Description: Evaluates the number of times a set of rasters is
#              equal to another raster on a cell-by-cell basis
# 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
inValueRaster = "cost"
inRaster01 = "degs"
inRaster02 = "negs"
inRaster03 = "fourgrd"

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

# Execute EqualToFrequency
outETF = EqualToFrequency(inValueRaster, [inRaster01, inRaster02, inRaster03])

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

Environments

Licensing information

  • Basic: Requires Spatial Analyst
  • Standard: Requires Spatial Analyst
  • Advanced: Requires Spatial Analyst

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