Plus (Spatial Analyst)

Available with Spatial Analyst license.

Available with Image Analyst license.

Available with 3D Analyst license.

Summary

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

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.

• In ArcPy, if both inputs are multidimensional rasters with the same number of variables, the tool 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 common dimension but no uncommon dimensions.

  If both inputs have one variable but different names, set the matchMultidimensionalVariable geoprocessing environment to False to perform the operation.

  In ArcPy, 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 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

Label	Explanation	Data Type
Output raster	The output raster. The cell values are the sum of the first input added to the second.	Raster

Python

Plus(in_raster_or_constant1, in_raster_or_constant2)

Name	Explanation	Data 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

Name	Explanation	Data 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")

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

Licensing information

• Basic: Requires Spatial Analyst or Image Analyst or 3D Analyst
• Standard: Requires Spatial Analyst or Image Analyst or 3D Analyst
• Advanced: Requires Spatial Analyst or Image Analyst or 3D Analyst