Minus (Spatial Analyst)

Summary

Subtracts the value of the second input raster from the value of the first input raster on a cell-by-cell basis.

Illustration

OutRas = Minus (InRas1, InRas2)

Usage

• The order of inputs is relevant for this tool.

• If both inputs are integer, the output will be an integer raster; otherwise, it will be a floating-point raster.

• 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 tool 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 tool will perform the operation using the constant value for each band in the multiband input, and the output will be a multiband raster.

• If both inputs are multidimensional raster data with the same number of variables, the tool will perform the operation for all slices with the same dimension value. The output will be a multidimensional raster in CRF format. The variables in the inputs must have at least one common dimension and one common dimensional value for this tool to process; otherwise, an error will occur.

  If both inputs have one variable but different names, uncheck the Match Multidimensional Variable geoprocessing environment (set arcpy.env.matchMultidimensionalVariable = False in Python) before running the tool.

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

• In map algebra, the equivalent operator symbol for this tool is "-" (link).

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

Parameters

Dialog

Label	Explanation	Data Type
Input raster or constant value 1	The input from which to subtract the values in the second input. A number can be used as an input for this parameter, provided a raster is specified for the other parameter. To specify a number for both inputs, the cell size and extent must first be set in the environment.	Raster Layer; Constant
Input raster or constant value 2	The input values to subtract from the values in the first input. A number can be used as an input for this parameter, provided a raster is specified for the other parameter. To specify a number for both inputs, the cell size and extent must first be set in the environment.	Raster Layer; Constant

Return Value

Label	Explanation	Data Type
Output raster	The output raster. The cell values are the result of subtracting the second input from the first.	Raster

Python

Minus(in_raster_or_constant1, in_raster_or_constant2)

Name	Explanation	Data Type
in_raster_or_constant1	The input from which to subtract the values in the second input. A number can be used as an input for this parameter, provided a raster is specified for the other parameter. To specify a number for both inputs, the cell size and extent must first be set in the environment.	Raster Layer; Constant
in_raster_or_constant2	The input values to subtract from the values in the first input. A number can be used as an input for this parameter, provided a raster is specified for the other parameter. To specify a number for both inputs, the cell size and extent must first be set in the environment.	Raster Layer; Constant

Return Value

Name	Explanation	Data Type
out_raster	The output raster. The cell values are the result of subtracting the second input from the first.	Raster

Code sample

Minus example 1 (Python window)

This example subtracts the values of the second input raster from the first.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outMinus = Minus("degs", "negs")
outMinus.save("C:/sapyexamples/output/outminus")

Minus example 2 (stand-alone script)

This example subtracts the values of the second input raster from the first.

# Name: Minus_Ex_02.py
# Description: Subtracts the value of the second input raster from the
#              value of the first input 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
inRaster1 = "degs"
inRaster2 = "negs"

# Execute Minus
outMinus = Minus(inRaster1, inRaster2)

# Save the output 
outMinus.save("C:/sapyexamples/output/outminus.tif")

Environments

Auto Commit, Cell Size, Cell Size Projection Method, Compression, Current Workspace, Extent, Geographic Transformations, Mask, Output CONFIG Keyword, Output Coordinate System, Scratch Workspace, Snap Raster, Tile Size