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Thread: Zonal Histogram fails to create table

  1. #1
    James Prieger
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    Default Zonal Histogram fails to create table

    When running the Zonal Histogram tool, the Results window say the tool executes successfully after 4.5 hours, but the output table is not created. Right clicking on the output table in the Results window gives the options "add to display" and "copy location"; the first does nothing and the second has the right path and filename but the file doesn't exist.
    Here's the really puzzling part: There are no error messages.
    Has anyone run into this before?

    I've tried Zonal Histogram many different ways for this task, and nothing works well. Outputting to a table in a file gdb worked once, but then ArcMap and ArcCatalog choke trying to export the output table to DBF.

    Details:
    ArcGIS 10 sp4
    Input zones: a layer that is a subset of polygons from a polygon shapefile
    Input raster: a large (16 GB) IMG raster
    desired output table: DBF file stored to a directory (not a geodatabase). Table should have 251 fields (yes, carefully chosen to respect the 255 field limit for dbf).

  2. #2
    Pavan Yadav
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    Default Re: Zonal Histogram fails to create table

    Quote Originally Posted by prieger View Post
    When running the Zonal Histogram tool, the Results window say the tool executes successfully after 4.5 hours, but the output table is not created. Right clicking on the output table in the Results window gives the options "add to display" and "copy location"; the first does nothing and the second has the right path and filename but the file doesn't exist.
    Here's the really puzzling part: There are no error messages.
    Has anyone run into this before?

    I've tried Zonal Histogram many different ways for this task, and nothing works well. Outputting to a table in a file gdb worked once, but then ArcMap and ArcCatalog choke trying to export the output table to DBF.

    Details:
    ArcGIS 10 sp4
    Input zones: a layer that is a subset of polygons from a polygon shapefile
    Input raster: a large (16 GB) IMG raster
    desired output table: DBF file stored to a directory (not a geodatabase). Table should have 251 fields (yes, carefully chosen to respect the 255 field limit for dbf).
    Hi James,
    Looks like the issue you are experiencing is data specific or you might even be hitting a hardware limit. Also, the tool might fail with some formats (including dbf and info table) if a graph was being specified. So could you please first try to see what happens if you specify a graph name?

    Because a fairly large dataset (~16GB) is involved, and there could be other variable associated I think it would be better if you could work with our Support Services, here you can find the contact information. Please note that to get services from our Support Services, you must be on current maintenance. Just in case if you are not on current maintenance, please send me an email at pyadav dot esri dot com so that we can discuss other options.

    Thanks
    Pavan

  3. #3
    James Prieger
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    Default Re: Zonal Histogram fails to create table

    Quote Originally Posted by pyadav1 View Post
    Hi James,
    ... Also, the tool might fail with some formats (including dbf and info table) if a graph was being specified. So could you please first try to see what happens if you specify a graph name?
    Just to make sure I understand the point about the graph name--I was not requesting a graph, just the table. Do you mean that specifying a graph name and having the tool calculate and save it might help? Or just that if I were requesting a graph, then there would be naming issues.

    Thanks,
    Jim

  4. #4
    Pavan Yadav
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    Default Re: Zonal Histogram fails to create table

    Quote Originally Posted by prieger View Post
    Just to make sure I understand the point about the graph name--I was not requesting a graph, just the table. Do you mean that specifying a graph name and having the tool calculate and save it might help? Or just that if I were requesting a graph, then there would be naming issues.

    Thanks,
    Jim
    Hi Jim,
    Sorry for the wrong statement and question. Actually, we have seen some issues that indicate that the tool might fail with some formats (including dbf and info table) if a graph is being specified. Actually, I wanted to to know if you were requesting a graph also. Now, I understand that you were not. Thank you for the clarification. Based on this information, i am not sure why the tool is not working. I could investigate this issue if you could provide me with more information i.e. a sample dataset or direction to create a similar data for my tests.

    Thanks
    Pavan

  5. #5
    Curtis Price

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    Default Re: Zonal Histogram fails to create table

    Quote Originally Posted by pyadav1 View Post
    I've tried Zonal Histogram many different ways for this task, and nothing works well. Outputting to a table in a file gdb worked once, but then ArcMap and ArcCatalog choke trying to export the output table to DBF.
    Dbase is extremely limited for large files. Microsoft Query (maybe Jet too -- used by ArcGIS) only supports 199 fields, even though the file format supports 255. There's also that pesky 4000-byte record length, regardless of number of fields. In your case you also may be reaching the 2GB file size limit. (Note dbf is entirely uncompressed storage, a 25 character field takes up 25 bytes.)

    We have been warned in the help, here's the link, for the thread:

    Geoprocessing considerations for shapefile output

  6. #6
    James Prieger
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    Default Re: Zonal Histogram fails to create table

    Thanks for the suggestions. It turned out that the cause was something else, which appears to be a bug in the tool, and so is worth documenting here for future users.

    The input zone layer to the Zonal Histogram was a layer created from a selection from a source layer. That is, Layer2 (the input defining the zones for the Zonal Histogram tool) was created in a map by selecting 250 features from Layer1 (a complete set of US ZIP code polygons), then doing right click/Selection/Create layer from selected features. However, even though Layer2 has only 250 features that display on the map or show up in its attribute table, the Zonal Histogram tool went a grabbed all the layers from Layer1 to use as the zones! So instead of the expected 251 fields in the histogram table, there were about 30,000, and that is why no DBF or MDB table could be created.

    The upshot: when using a map layer defined as a subset of a source layer, Zonal Histogram will use the source layer instead to define the zones.

    p.s. my ultimate resolution to extract the data as required was to run the histogram, save output to a file GDB in the default format, write a python script that reversed the rows and columns of that huge zonal histogram, and write the table to a CSV file, which I could then manipulate in Excel. While a table with 30000 columns is almost impossible to do anything with, a table with 30000 rows is no problem.

  7. #7
    Pavan Yadav
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    Default Re: Zonal Histogram fails to create table

    Hi Jim,

    Thank you for providing detailed description of the issue. I tested this at 10.0 SP 4 and 10.1 pre-release, and found that this has been fixed at 10.1 but exists at 10.0 SP 4. We consider this behavior a bug. We have log a bug for this, here is its bug ID NIM080750. It should be published soon and you can track its status from our Support page. As I said before, we would be happy to test with you data as well, if you think this could be a data specific issue.

    Thanks again for bringing this to our attention.

    Regards.
    Pavan

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