Over (Spatial Analyst)

Available with Spatial Analyst license.

Available with Image Analyst license.

Summary

For the cell values in the first input that are not 0, the output value will be that of the first input. Where the cell values are 0, the output will be that of the second input raster.

Illustration

Over illustration
OutRas = Over(InRas1, InRas2)

Usage

  • Two inputs are necessary for this logical evaluation to take place.

  • The order of inputs is relevant 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.

  • See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.

Parameters

LabelExplanationData Type
Input raster or constant value 1

The input for which cell values of 0 will be replaced with the value from the second 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
Input raster or constant value 2

The input whose value will be assigned to the output raster cells where the first input value is 0.

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.

Raster

Over(in_raster_or_constant1, in_raster_or_constant2)
NameExplanationData Type
in_raster_or_constant1

The input for which cell values of 0 will be replaced with the value from the second 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
in_raster_or_constant2

The input whose value will be assigned to the output raster cells where the first input value is 0.

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.

Raster

Code sample

Over example 1 (Python window)

This example performs an Over operation on two Grid rasters.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outOver = Over("degs", "negs")
outOver.save("C:/sapyexamples/output/outover2")
Over example 2 (stand-alone script)

This example performs an Over operation on two Grid rasters.

# Name: Over_Ex_02.py
# Description: Returns those values from the first input that are
#    non-zero; otherwise, returns the value from the second input
# 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 = "degs"
inRaster2 = "negs"

# Execute Over
outOver = Over(inRaster1, inRaster2)

# Save the output 
outOver.save("C:/sapyexamples/output/outover")

Licensing information

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

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