Minus

Usage tips

Command line and Scripting

• The order of input is relevant in the subtraction expression.

• If both input values are integers, the output values will be integers; otherwise, the output will be a floating-point value.

• A number can be used as an input; however, the cell size and extent must first be set in the environment.

• The following environment settings affect this tool:

  • General: Current Workspace, Scratch Workspace, Output Coordinate system, Output Extent (and Snap Raster).
  • Raster Analysis: Cell size, Mask.
  • Raster Storage: See the Raster Storage settings for the particular output raster format selected.

ArcObjects

• The order of input is relevant in the subtraction expression.

• If both input values are integer, the output values will be integer; otherwise, the output will be floating point.

• The output from the ArcObjects method is a raster object.

• A number cannot be used as input to the ArcObjects method. If a constant number must be passed to the method, create a constant raster using IRasterMakerOp::MakeConstant, then pass the results to the method.

Command line syntax
An overview of the Command Line window
Minus_sa <in_raster_or_constant1> <in_raster_or_constant2> <out_raster>

Command line example

Minus_sa C:/data/ras_1 C:/data/ras_2 C:/data/final_1

Scripting syntax
About getting started with writing geoprocessing scripts
Minus_sa (in_raster_or_constant1, in_raster_or_constant2, out_raster)

Script example

# Minus_sample.py
# Description: 
#   Subtracts the values of two rasters on a cell-by-cell basis.
# Requirements: None
# Author: ESRI
# Date: Sept 6, 2005
# Import system modules
import arcgisscripting

# Create the Geoprocessor object
gp = arcgisscripting.create()

try:
    # Set the input raster dataset
    inRaster1 = "C:/data/ras_1"
    inRaster2 = "C:/data/ras_2"

    # Set the output raster name
    outRaster = "C:/data/final_1"

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

    # Process: Minus
    gp.Minus_sa(inRaster1, inRaster2, outRaster)

except:
    # If an error occurred while running a tool, then print the messages.
    print gp.GetMessages()

Map Algebra syntax
See -

ArcObjects syntax
IMathOp::Minus (geoDataset1 As IGeoDataset, geoDataset2 As IGeoDataset) As IGeoDataset

ArcObjects example

' Create the MathOps object
Dim pMathOp As IMathOp
Set pMathOp = New RasterMathOps

' Declare the input geoDataset1 object
Dim pInputDataset1 As IGeoDataset

' Calls function to open a raster dataset from disk
Set pInputDataset1 = OpenRasterDataset ("D:\SpatialData", "inputraster1")

' Declare the input geoDataset2 object
Dim pInputDataset2 As IGeoDataset

' Calls function to open a raster dataset from disk
Set pInputDataset2 = OpenRasterDataset ("D:\SpatialData", "inputraster2")

' Declare the output raster object
Dim pOutputRasterAs IGeoDataset

' Calls the method
Set pOutputRaster = pMathOp.Minus (pInputDataset1, pInputDataset2)