| Operand | Explanation | Data Type |
in_raster_or_constant | The input raster to be negated (multiplied by -1). | Raster Layer | Constant |
Available with Spatial Analyst license.
Available with Image Analyst license.
Summary
Changes the sign of the cell values (multiplies by -1) of the input raster on a cell-by-cell basis.
Illustration
Discussion
When using an operator with a raster input, the result will be a raster. However, if all inputs are numbers, the result is a number.
When multiple operators are used in an expression, they are not necessarily executed in left-to-right order. The operator with the highest precedence value will be executed first. For more information, see the operator precedence table in Work with operators in Map Algebra. You can use parentheses to control the execution order.
If the input is integer, the output will be integer. If the input is floating point, the output will be floating point.
If the input is a multiband raster, the output will be a multiband raster. The operator will perform the operation on each band in the input.
If the input is a multidimensional raster, all slices from all variables will be processed, and the output will be a multidimensional raster.
Parameters
Code sample
This sample changes the sign of the values in the input raster.
import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outNegate = - Raster("degs")
outNegate.save("C:/sapyexamples/output/outneg")This sample changes the sign of the values in the input raster.
# Name: Op_Negate_Ex_02.py
# Description: Changes the sign (multiplies by -1) of the cell values
# of the 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
inRaster = Raster("degs")
# Execute Negate
outNegate = -(inRaster)
# Save the output
outNegate.save("C:/sapyexamples/output/outnegate")