Is Null (Spatial Analyst)

Available with Spatial Analyst license.

Available with Image Analyst license.

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.

• If the input is a multiband raster, the output will be a multiband raster. The tool will perform the operation on each band in the input.

• See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.

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 identifies with an integer 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

# 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"

# Execute IsNull
outIsNull = IsNull(inRaster)

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

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