/ (Division) operator

Available with Spatial Analyst license.

Available with Image Analyst license.

Summary

Divides the values of two rasters on a cell-by-cell basis.

Illustration

Divide operator illustration
OutRas = Raster("InRas1") / Raster("InRas2")

Discussion

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

When there are multiple operators in an expression, the operators are not necessarily run in left-to-right order. The operator with the highest precedence value will be run first. For more information, see the operator precedence table in Work with operators in map algebra. Use parentheses to control the run order.

The order of the input is relevant for this operator.

When a number is divided by zero, the output result is NoData.

The floating-point division of Python 3 is used for this operator, and the output will always be a floating-point value. For example, if 3 is divided by 2, the output is 1.5. Use the // (Integer Division) operator produce an integer output.

Another way to perform the divide operation is a /= b, which is an alternative way to write a = a / b.

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, the operator will perform the operation on each band from one input, and the output will be a multiband raster. The number of bands in each multiband input must be the same.

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, and the output will be a multiband raster.

If both inputs are multidimensional rasters with the same number of variables, the operator will perform the operation for all slices with the same dimension value, and the output will be a multidimensional raster. The variables in the inputs must have the same dimensions or a common dimension but no uncommon dimensions.

If both inputs have one variable but different names, set the Match Multidimensional Variable environment to False to perform the operation.

If one of the inputs is a multidimensional raster and the other input is a constant, the operator will perform the operation for all slices for all variables against the constant value, and the output will be a multidimensional raster.

Parameters

OperandExplanationData Type
in_raster_or_constant1

The input whose values will be divided by the second input.

If the first input is a raster and the second is a scalar, an output raster is created with each input raster value being divided by the scalar value.

Raster Layer | Constant
in_raster_or_constant2

The input whose values the first input are to be divided by.

If the first input is a scalar and the second is a raster, an output raster is created, with each input raster value being divided into the scalar value.

Raster Layer | Constant

Code sample

/ (Division) example 1 (Python window)

This sample divides the values of the first input raster by the second.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outDivide = Raster("degs") / Raster("negs")
outDivide.save("C:/sapyexamples/output/outdivide")
/ (Division) example 2 (stand-alone script)

This sample divides the values of the first input raster by the second.

# Name: Op_Divide_Ex_02.py
# Description: Divides the values of two rasters 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
inRaster01 = Raster("elevation")
inRaster02 = Raster("landuse")

# Execute Divide
outDivide = inRaster01 / inRaster02

# Save the output 
outDivide.save("C:/sapyexamples/output/outdivide2")

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