Plus (Spatial Analyst)

Summary

Adds (sums) the values of two rasters on a cell-by-cell basis.

Illustration

Plus illustration
OutRas = Plus (InRas1, InRas2)

Usage

  • The order of inputs is irrelevant 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.

Parameters

LabelExplanationData Type
Input raster or constant value 1

The input whose values will be added to.

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 whose values will be added to 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

LabelExplanationData Type
Output raster

The output raster.

The cell values are the sum of the first input added to the second.

Raster

Plus(in_raster_or_constant1, in_raster_or_constant2)
NameExplanationData Type
in_raster_or_constant1

The input whose values will be added to.

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 whose values will be added to 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

NameExplanationData Type
out_raster

The output raster.

The cell values are the sum of the first input added to the second.

Raster

Code sample

Plus example 1 (Python window)

This example adds the values of two Grid rasters and outputs the result as an IMG raster.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outPlus = Plus("degs", "negs")
outPlus.save("C:/sapyexamples/output/outplus.img")
Plus example 2 (stand-alone script)

This example adds the values of two Grid rasters and outputs the result as a Grid raster.

# Name: Plus_Ex_02.py
# Description: Adds 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
inRaster1 = "cost"
inRaster2 = "degs"

# Execute Plus
outPlus = Plus(inRaster1, inRaster2)

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

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