Is Null (Spatial Analyst)

Summary

Determines which values from the input raster are NoData on a cell-by-cell basis.

Returns a value of 1 if the input value is NoData and 0 for cells that are not.

Illustration

OutRas = IsNull(InRas1)

Usage

• Is Null can be used along with the Con tool to change NoData cells to a value.

Syntax

IsNull (in_raster)

Parameter	Explanation	Data Type
in_raster	The input raster being tested to identify the cells that are NoData (null). The input can be either integer or floating point type.	Raster Layer

Return Value

Name	Explanation	Data Type
out_raster	The output raster. The output raster identifies with a value of 1 which cells in the input are NoData. If the input is any other value, the output is 0.	Raster

Code Sample

IsNull example 1 (Python window)

This example identifies which cells in the input raster are NoData, and outputs the result as an IMG raster.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outIsNull = IsNull("degs")
outIsNull.save("C:/sapyexamples/output/outisnull.img")

IsNull example 2 (stand-alone script)

This example identifies which cells in the input raster are NoData, and outputs the result as a GRID raster.

# Name: IsNull_Ex_02.py
# Description: Find which cell values of the input raster are NoData
# 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
inRaster = "degs"

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

# Execute IsNull
outIsNull = IsNull(inRaster)

# Save the output 
outIsNull.save("C:/sapyexamples/output/outisnull")

Environments

Cell Size, Current Workspace, Mask, Output Coordinate System, Extent, Scratch Workspace, Snap Raster

Licensing Information

ArcView: Requires Spatial Analyst

ArcEditor: Requires Spatial Analyst

ArcInfo: Requires Spatial Analyst