Plus (Spatial Analyst)

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.

• In Map Algebra, the equivalent operator symbol for this tool is "+" (link).

Syntax

Plus (in_raster_or_constant1, in_raster_or_constant2)

Parameter	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 be able 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 be able 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
# Author: ESRI

# 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"

# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")

# Execute Plus
outPlus = Plus(inRaster1, inRaster2)

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

Environments

Cell Size, Current Workspace, Mask, Output Coordinate System, Extent, Scratch Workspace, Snap Raster

Licensing Information

ArcView: Requires Spatial Analyst or 3D Analyst

ArcEditor: Requires Spatial Analyst or 3D Analyst

ArcInfo: Requires Spatial Analyst or 3D Analyst