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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, 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.

The order of input is relevant for this operator.

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

The exact division technique used by this operator depends on the application being used when performing it.

In ArcMap, the divide operator employs the integer division technique of Python 2, where only the integer quotient is retained. If both inputs are integers, the operator performs an integer division, and the output will be an integer. For example, if 3 is divided by 2, the output is 1, or if -3 is divided by 2, the output is -2. If either input is of floating-point type, the divide operator performs a floating-point division, and the output will be a floating-point value. For example, if 3 is divided by 2.0, the output is 1.5.

In ArcGIS Pro, the floating-point division of Python 3 is always 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.

Note:

Keep this difference in mind if you are migrating from ArcGIS Desktop to ArcGIS Pro, or you will be working in a mixed environment of both. You can use the // (Integer Division) operator if it is important to maintain the integer output.

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

Syntax

in_raster_or_constant1 / in_raster_or_constant2
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

Return Value

NameExplanationData Type
out_raster

The output raster object.

The cell values are the quotient of the first input raster (dividend) divided by the second input (divisor).

Raster

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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