Zonal Statistics can't find field name

Question

I have a model in model builder that at some point does a Zonal Statistics between two rasters. Last time I used the model was working fine but today, when I tried to run the model, it complained that zone field is not correct. I have the zone field set to Value (the zone mape is a raster). Has anyone seen this error before? Could it be due to some bad instalation (I installed some other flavor of python after installing ArcMap.

Thanks
Daniel

DanielVictoria · Answer

Does your zone raster have an attribute table?  I would check there first, occassionally even if the raster is an integer/discrete dataset, there is no raster attribute table created and must be created afterwards.  Use the Build Raster Attribute Table if you do not see a raster attribute table to open.

BINGO!! The smaller raster had an attribute table build by default but the one with 266k zones did not. Building the attribute table made the process go through. Will put that step into the model routine so I don't hit that problem anymore.

As a tip, couldn't the error message state that the attribute table was not found instead of saying that the chosen field was not found. Because in my (dumb) mind, the error "Could not get field name" tells me there is a table but the chosen field is not there...

Thanks for all the help
Daniel

DanielVictoria · Answer

More information. The procedure worked in a smaller region, with 11630 areas, but it's chocking when I give the full dataset that has 256688 distinct zones! Is there a limit on the number of zones ZonalStatistics can manage? How can I overcome this? And why is the error message not related to the problem?

Thanks

JeffreySwain · Answer

Does your zone raster have an attribute table?  I would check there first, occassionally even if the raster is an integer/discrete dataset, there is no raster attribute table created and must be created afterwards.  Use the Build Raster Attribute Table if you do not see a raster attribute table to open.