== (Relational Equal To) operator

Available with Spatial Analyst license.

Available with Image Analyst license.

Summary

Performs a relational equal-to operation on two inputs on a cell-by-cell basis within the Analysis window.

Illustration

Equal To (Relational) operator illustration
OutRas = Raster("InRas1") == Raster("Const2Ras")

Discussion

Returns 1 for cells where the first raster equals the second raster and 0 for cells where it does not.

When using an operator with a raster input the result will be a raster. However, if all inputs are numbers, then the result is a number.

When multiple operators are used in an expression, they are not necessarily executed in left-to-right order. The operator with the highest precedence value will be executed first. For more information on operator precedence, see operator precedence table. You can use parentheses to control the execution order.

Boolean (~, &, ^, |) operators have a higher precedence level than Relational (<, <=, >, >=, ==, !=) operators. Therefore, when Boolean operators are used in the same expression as Relational operators, the Boolean operators will be executed first. To change the order of execution, use parentheses.

When multiple Relational and/or Boolean operators are used consecutively in a single expression, in some cases it may fail to execute. To avoid this potential problem, use appropriate parentheses in the expression so that the execution order of the operators is explicitly defined. For more information, see Complex Statement Rules.

Two inputs are necessary for the evaluation to take place.

The order of input is irrelevant for this operator.

Output values are always integer.

If both inputs are single band rasters, or one of the inputs is a constant, the output will be a single band raster.

If both inputs are multiband rasters, or one of the inputs is a constant, the output will be a multiband raster. The number of bands in each multiband input must be the same.

The operator will perform the operation on each band from one input against the corresponding band from the other input. If one of the inputs is a multiband raster and the other input is a constant, the operator will perform the operation against the constant value for each band in the multiband input.

Syntax

in_raster_or_constant1 == in_raster_or_constant2
OperandExplanationData Type
in_raster_or_constant1

The input that will be compared to for equality by the second input.

If one of the inputs is a raster and the other is a scalar, an output raster is created with the evaluation being performed for each cell in the input raster.

Raster Layer | Constant
in_raster_or_constant2

The input that will be compared from for equality by the first input.

If one of the inputs is a raster and the other is a scalar, an output raster is created with the evaluation being performed for each cell in the input raster.

Raster Layer | Constant

Return Value

NameExplanationData Type
out_raster

The output raster object.

Where cell values in the first input are equal to that of the second input, the output cell value will be 1. If the values are not equal, the output value will be 0.

Raster

Code sample

== (Equal To) example 1 (Python window)

This sample performs an Equal To operation on two input rasters.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outEqualTo = Raster("degs") == Raster("negs")
outEqualTo.save("C:/sapyexamples/output/outequalto.tif")
== (Equal To) example 2 (stand-alone script)

This sample performs an Equal To operation on two input rasters.

# Name: Op_EqualTo_Ex_02.py
# Description: Performs a relational equal-to operation on two inputs
#              on a cell-by-cell basis within the Analysis window
# 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
inRaster1 = Raster("degs")
inRaster2 = Raster("negs")

# Execute EqualTo
outEqualTo = inRaster1 == inRaster2

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

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