cmclapp

Subject: How to increase Network Analyst solve speeds in a Python loop

Discussion created by cmclapp on Apr 14, 2011
Latest reply on Apr 25, 2011 by cmclapp
I'm working on producing a large OD Matrix (55,000 x 55,000) using ArcGIS 10.  I have written a script in Python so that I don't run into memory issues.  The script that makes the OD layer, adds all 55,000 origins, then enters a loop, adds 100 destinations, solves, and outputs the data.  The only problem is that each iteration of the loop takes a long time to complete (mostly to solve).

I've already

1)  defined a hierarchy
2)  hard coded my cost attributes into the network as the smallest useful data
types (floats)
3)  dissolved the network
4)  calculated my origin and destination locations

Is there anything I can do to speed up the process?

Also, I've noticed that solve times increase with each iteration (at an increasing rate).  I believe that this may be because ArcGIS is writing to an ever increasing temp file.  Is there any way I can prevent this from happening?  I clear the previous destinations in each iteration of the loop, so I don't think that's part of the problem.

Thanks in advance!

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