[Qgis-developer] shapefile editing memory issue

[Thorp, Kelly]

Hello List:

I am developing a QGIS plug-in for the purpose of running simulation models for unique land units, as represented by polygons in a polygon shapefile.  Essentially, the plug-in uses spatial information in the polygon layer to write a simulation model input file.  It then uses Python's 'subprocess' module to call the model executable and run the simulation.  It then reads an output file generated by the model, sets the polygon shapefile to be editable, changes some attributes based on the model output, and then commits those changes.  Then repeating this in a loop for each feature in the polygon shapefile.

I've also included an optimization routine for the purpose of model calibration.  This essentially means doing the above procedures repeatedly tens or hundreds of thousands of times.   After each model simulation, the updated 'simulated' attribute values are compared with other attributes that contain 'observed' data.  The optimization then repeatedly adjusts the model parameters until simulated and observed data are in best agreement.

This process can take many hours or days, while I am repeatedly editing the shapefile and commiting the edits.  However, I am not adding or removing any features or attributes.  Problem is the memory slowly creeps up and if the optimization takes too long, I'll run out of memory and QGIS will crash. I notice that if my optimization routine does finish, I can completely shut down my plugin's dialog window, but the memory usage remains high.  This makes me think the problem is not in my plug-in.  Any ideas for me?

Thanks,
Kelly

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Kelly Robert Thorp, Ph.D., P.E.
Research Agricultural Engineer
USDA-ARS
U.S. Arid Land Agricultural Research Center
21881 N Cardon Lane
Maricopa, AZ  85138
520-316-6375 (Phone)
520-316-6330 (Fax)
kelly.thorp at ars.usda.gov
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~





This electronic message contains information generated by the USDA solely for the intended recipients. Any unauthorized interception of this message or the use or disclosure of the information it contains may violate the law and subject the violator to civil or criminal penalties. If you believe you have received this message in error, please notify the sender and delete the email immediately.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-developer/attachments/20120712/7c2db04d/attachment.html>