Test (Image Analyst)

Available with Spatial Analyst license.

Available with Image Analyst license.

Summary

Performs a Boolean evaluation of the input raster using a logical expression.

When the expression evaluates to true, the output cell value is 1. If the expression is false, the output cell value is 0.

Illustration

OutRas = Test(InRas1,"Value >= 2")

Usage

• The test is specified by an SQL expression in the Where clause.

• The Where clause uses an SQL query. See the following topics for more details on creating queries:

  • Build an SQL query
  • SQL reference for query expressions used in ArcGIS

• In order to use a {where_clause} in Python, it should be enclosed in quotes. For example, "Value > 5000".

  You can consult the help for more information on specifying a query in Python.

Syntax

Test(in_raster, where_clause)

Parameter	Explanation	Data Type
in_raster	The input raster on which the Boolean evaluation is performed, based on a logical expression.	Raster Layer
where_clause	The logical expression that will determine which input cells will return a value of true (1) and which will be false (0). The expression follows the general form of an SQL expression. An example of a where_clause is "VALUE > 100".	SQL Expression

Return Value

Name	Explanation	Data Type
out_raster	The output raster. The output cell values will be either 0 or 1.	Raster

Code sample

Test example 1 (Python window)

This example uses a Where clause to perform a Boolean operation on an input raster.

import arcpy
from arcpy import env
from arcpy.ia import *
env.workspace = "C:/iapyexamples/data"
outTest = Test("degs", "VALUE > 100")
outTest.save("C:/iapyexamples/output/outest.img")

Test example 2 (stand-alone script)

This example uses a Where clause to perform a Boolean operation on an input raster.

# Name: Test_Ex_02.py
# Description: Perform a Boolean evaluation of the input raster based
#              on a where clause
# 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
inRaster = "degs"
inWhereClause = "VALUE > 100"

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

# Execute Test
outTest = Test(inRaster, inWhereClause)

# Save the output 
outTest.save("C:/iapyexamples/output/outtest")

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

Licensing information

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