# Greater Than (Image Analyst)

Available with Spatial Analyst license.

Available with Image Analyst license.

## Summary

Performs a Relational greater-than operation on two inputs on a cell-by-cell basis.

Returns 1 for cells where the first raster is greater than the second raster and 0 for cells if it is not.

Learn more about how the Relational Math tools work

## Usage

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

• The order of inputs is relevant for this tool.

• 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.

• In map algebra, the equivalent operator symbol for this tool is ">" (link).

## Parameters

 Label Explanation Data Type Input raster or constant value 1 The input being tested to determine if it is greater than 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 against which the first input is tested to be greater than.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.The output cell values will be either integer 0 or 1, or NoData if any input cell value is NoData. Raster

`GreaterThan(in_raster_or_constant1, in_raster_or_constant2)`
 Name Explanation Data Type in_raster_or_constant1 The input being tested to determine if it is greater than 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 against which the first input is tested to be greater than.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.The output cell values will be either integer 0 or 1, or NoData if any input cell value is NoData. Raster

### Code sample

GreaterThan example 1 (Python window)

This example performs a Relational greater-than operation on two Grid rasters and outputs the result as an IMG raster.

``````import arcpy
from arcpy import env
from arcpy.ia import *
env.workspace = "C:/iapyexamples/data"
outGreaterThan = GreaterThan("degs", "negs")
outGreaterThan.save("C:/iapyexamples/output/outgt.img")``````
GreaterThan example 2 (stand-alone script)

This example performs a Relational greater-than operation on two Grid rasters.

``````# Name: GreaterThan_Ex_02.py
# Description: Performs a relational greater-than operation on two inputs
#              on a pixel-by-pixel basis within the Analysis window
# Requirements: Image Analyst Extension

# Import system modules
import arcpy
from arcpy import env
from arcpy.ia import *

# Set environment settings
env.workspace = "C:/iapyexamples/data"

# Set local variables
inRaster1 = "degs"
inRaster2 = "negs"

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

# Execute GreaterThan
outGreaterThan = GreaterThan(inRaster1, inRaster2)

# Save the output
outGreaterThan.save("C:/iapyexamples/output/outgt")``````

## Licensing information

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