Latest Contributions by curtvprice

If it's an integer raster, you can calculate the number of data cells by summing up COUNT in the raster table and subracting it from rows * columns. For floating grids, you must convert the cells to 0/1 with IsNull and sniff the COUNT value from the output raster RAT (I'd do that with a cursor for a table view generated for VALUE = 1). ... View more

how do I get the MIN of several grids in Map Algebra; neither MIN or MINIMUM in the help points to where that function is, and guessing the syntax only leads to error messages). Python map algebra requires new, case-sensitive syntax, and the names of the functions are the same as the tool names. I know this all seems very painful now but I think in the long run it is good to have one syntax for raster tools instead of 9.3's five (Raster calc, SOMA, MOMA, command window). CellStatistics (in_rasters_or_constants, {statistics_type}, {ignore_nodata}) 9.3 raster calculator: min([raster1],[raster2]) 10.0 map algebra: CellStatistics("raster1","raster2","MINIMUM") or, you can just run the CellStatistics tool dialog. ... View more

i click on it a blank/grey window pops up, not the dialogue window that everyone talks about Check out KB" rel="nofollow" target="_blank">http://support.esri.com/en/knowledgebase/techarticles/detail/33792]KB 33792 ... View more

The Mosaic and Mosaic To New Raster tools include functionality along these lines. Have you tried it? ... View more

Esri recently posted a neat approach to processing your one-to-many table (the one with dupes output from select by location): Geoprocessing Blog: Concatenate Row Values http://blogs.esri.com/Dev/blogs/geoprocessing/archive/2011/12/09/ConcatenateRowValues.aspx ... View more

On the vector side, to do this kind of modeling you need to combine the datasets using a tool like Intersect or Union -- the data need to all be in the same table. Then you could use Calculate Field to convert your attributes to weights and calculate a score in a single calculation. ... View more

Another method that may work is to open task manager (crl alt delete, select task manager), select the process for the status window and click the "switch to" button. ... View more

and it does not create my raster as I've predefined it, it creates one called divid_ras in my workspace (snip) Is it possible to have V10 just do what I ask?  create my rasters the way I define them, when the process runs and not create it's own names? If your scratch workspace is the same as the grid where you want to write things, when you run the .save it will simply rename your raster to what you want. If the scratch workspace and the workspace you're writing to are in different places, it will have to copy the output (which could be slow with large rasters). It's not all bad -- you don't need to worry about output names at all until you save the raster. base_max = Con(base_euc3, div, base_euc3, "VALUE < 1") base_max.save("mygridname") Also: but not until I run my next statement This is because the first grid isn't created until the you ask for it in a new map algebra statement or by calling the save method. This allows the python raster engine to optimize your processing as much as possible behind the scenes. ... View more

One thing I haven't tried yet is deleting feature layers... the rest of the code creates anywhere between 3-9 feature layers depending on how the output behaves.  I never bothered to delete these since they are deleted automatically when the session is over (right?), but they might be causing the lock since they are used for creating some of the shapefiles and grid rasters. I have seen the behavior Maarten has - no error message, but the datasets are not removed. I have found I do have to delete feature and raster layers with gp.Delete() before deleting their associated data sets to release os file locks. In 9.3, table views cannot be deleted, but fortunately they don't seem to hold a lock (but if there are relates, make sure they are dropped before you try to delete the dataset(s) in the table view or its relates). In 10.0 I've discovered you can (and need to) explicitly delete table views with gp.Delete(). Here's my method of managing temp files. If the delete is unsuccessful I just ignore any problems. If I have created a temp workspace and can't delete it, I add a check to see if it exists to warn the user that the temp workspace is still there. # note layer and views come BEFORE the data sets in the list lyrFeat,lyrRast,tvTable,tmpFeat,tmpRast = [None] * 5 ... try:   # work goes here except:   ... finally:   try:      del Row, Rows # any cursors deleted here   except:     pass   # the following is list copied and pasted from above   for f in lyrFeat,lyrRast,tvTable,tmpFeat,tmpRast:     try:        if f: gp.Delete(f)     except:       pass   ... View more

Thanks for the tip and sample code... I do store every return in a variable, but in the first go of the 'while' loop my script needs to reset one of the variables to an empty string, whereas it needs to have the original input for the second go. I thought the passed arguments to arcpy.GetParameterAsText() would persist all through the script (I've tried it with shorter version of the script - including the while loop - and that seems to work). Any more ideas? It's possible that if you run another tool in the script that's going to reset the parameter vector. I agree that capturing the information in one section of your script - once - is much safer. A thing to consider is whether there is something in your tool that lends it self to parameter validation code. ... View more

Have you considered using the geoprocessor? In general it is a lot less painful to create a geoprocessor object and throw the tool at it. ... View more

Yes, please! This is required for USGS publication standards (and the many standards that agree with it!) I understand this capability is available in Producting Mapping but this should be available in ArcGIS core. ... View more

(I) don't see why my definition would have failed. Did you try this? Since your input field is text value you may need to put it in quotes. I believe the actual value gets substituted in before the Python expression is interpreted. UTM_North = utmn("!MERIDIAN_NAME_TEXT!") ... View more

See my post for a method to get to $$ROWMAP using the unsupported back door to MOMA in 10.0. (Hi Tim!!) [thread]45087[/thread] As for the 32-bit precision issue - you are kind of stuck there as the tools were all written to work on grid floats (32-bit). Putting a raster into a high-precision raster stored in the file geodatabase may help somewhat (because of the new direct read/write at 10.0) - but probably only for some tools. Can your numpy arrays get bigger than 4GB? I would think they'd be limited by the fact that you need to use 32-bit python with ArcGIS. To do what you want effectively you may have to resort to what ESRI does with large data sets (vector and raster) -- tile your data (you could merge the results back together with  Mosaic pretty easily). ... View more