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

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.

• If both inputs are multidimensional raster data with the same number of variables, the tool will perform the operation for all slices with the same dimension value. The output will be a multidimensional raster in CRF format. The variables in the inputs must have at least one common dimension and one common dimensional value for this tool to process; otherwise, an error will occur.

  If both inputs have one variable but different names, uncheck the Match Multidimensional Variable geoprocessing environment (set arcpy.env.matchMultidimensionalVariable = False in Python) before running the tool.

  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

Dialog

Label	Explanation	Data 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

Label	Explanation	Data Type
Output raster	The output raster.	Raster

Python

Over(in_raster_or_constant1, in_raster_or_constant2)

Name	Explanation	Data 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

Name	Explanation	Data 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")

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