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.

• In ArcPy, if the input is a multidimensional raster, all slices from all variables will be processed, and the output will be a multidimensional raster.

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

Parameters

Dialog

Label	Explanation	Data Type
Input 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

Label	Explanation	Data Type
Output 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

Python

IsNull(in_raster)

Name	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