Error: Operation Failed [using Zonal Statistics]

Article ID:	18414
Software:	ArcGIS - ArcEditor 8.1, 8.1.2, 8.2, 8.3, 9.0, 9.1, 9.2 ArcGIS - ArcInfo 8.1, 8.1.2, 8.2, 8.3, 9.0, 9.1, 9.2 ArcGIS - ArcView 8.1, 8.1.2, 8.2, 8.3, 9.0, 9.1, 9.2
Platforms:	Windows NT 4.0, 2000

Error Message

When running the Zonal Statistics function in Spatial Analyst, the following error message may occur:

"Operation Failed"

Cause

The zone raster dataset might not have an attribute table. Zonal Statistics requires the zone dataset contain an attribute table.

Solution or Workaround

To create an Attribute Table for the zone dataset, add the layer to the Raster Calculator, [Inlayer], and evaluate.

This procedure creates a temporary raster with the same values as the original layer and with an attribute table. Using this output raster as the zone dataset produces an output from the Zonal Statistics function.

It is recommended that integer rasters have a permanent attribute table.

-NOTE-
Under certain conditions, the attribute table will not be automatically generated when an operation creates a Grid raster.

For more details on these conditions, and instructions on how to force the creation of the attribute table, see: -show me-

Summary

A value attribute table (VAT) is built by default for any integer raster that results from an expression, if the range of values (maximum minus minimum) in the raster is less than 100,000 or if the number of unique values in the raster is less than 500.

If the range is less than 100,000, the number of unique values in the raster can be as large as 100,000.

If the range is greater than 100,000, a VAT will still be built if the number of unique values is less than 500.

If the range of values is greater than 100,000 and the number of unique values are greater than 500, then no VAT is automatically built.

At ArcGIS 9.0, the VAT is not created for multitiled rasters. A multitiled raster is usually created when the number of cells times the number of bytes per cell is close to 2 GB. Multitiled raster can be identified by looking in the workspace folder. If there is more than one wNNNNNNx.adf (N = numeric value) file, then the raster is multitiled.

At ArcGIS 9.1, the VAT is created for multitiled rasters.

A bug was introduced, in ArcGIS 9.1, for the BUILDVAT command and a work around is to use
BUILDVAT yourRaster REBUILD_STA

Procedure

Below are two options available to build a VAT.

The BUILDVAT command is available in Workstation and from the Raster Calculator in the Spatial Analyst toolbar (available in ArcMap) as well as in the Multi Output Map Algebra tool.
There is also a script available to do a Build VAT in the Geoprocessing framework of ArcGIS. To download the script, click the link to the BuildVAT Geoprocessing Tool.

Related Information

Operation Failed [Index of common causes]
Below is a list of all common causes that may generate the error message: "Operation Failed" The articles below address the various causes, and provide a workaround when available. Please note that it may be necessary to log on to our suppo...

Created: 4/21/2001
Last Modified: 9/17/2008