Greater Than Frequency (Spatial Analyst)

Summary

Evaluates on a cell-by-cell basis the number of times a set of rasters is greater than another raster.

Illustration

Greater Than Frequency illustration
OutRas = GreaterThanFrequency(ValRas, [InRas1, InRas2, InRas3])

Usage

Syntax

GreaterThanFrequency (in_value_raster, in_rasters)
ParameterExplanationData Type
in_value_raster

For each cell location in the input value raster, the number of occurrences (frequency) where a raster in the input list has a greater value is counted.

Raster Layer
in_rasters
[in_raster,...]

The list of rasters that will be compared against the value raster.

Raster Layer

Return Value

NameExplanationData Type
out_raster

The output raster.

For each cell in the output raster, the value represents the number of times that the corresponding cells in the list of rasters is greater than the value raster.

Raster

Code Sample

GreaterThanFrequency example 1 (Python window)

This example evaluates the number of times a set of input GRID rasters is greater than another raster and outputs the result as a TIFF raster.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outGTF = GreaterThanFrequency("cost", ["degs", "negs", "fourgrd"])
outGTF.save("C:/sapyexamples/output/outgtf.tif")
GreaterThanFrequency example 2 (stand-alone script)

This example evaluates the number of times a set of input GRID rasters is greater than another raster and outputs the result as a GRID raster.

# Name: GreaterThanFrequency_Ex_02.py
# Description: Evaluates the number of times a set of rasters is
#              greater than another raster on a cell-by-cell basis
# Requirements: Spatial Analyst Extension
# Author: ESRI

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

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

# Set local variables
inValueRaster = "cost"
inRaster01 = "degs"
inRaster02 = "negs"
inRaster03 = "fourgrd"

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

# Execute GreaterThanFrequency
outGTF = GreaterThanFrequency(inValueRaster, [inRaster01, inRaster02, inRaster03])

# Save the output 
outGTF.save("C:/sapyexamples/output/outgtf")

Environments

Related Topics

Licensing Information

ArcView: Requires Spatial Analyst
ArcEditor: Requires Spatial Analyst
ArcInfo: Requires Spatial Analyst

6/29/2011