Martin Davis <mtnclimb <at> telus.net> writes: > > Have a look at: > > http://www.vividsolutions.com/jts/tests/index.html > > This is a visual interface to the JTS Test Suite, which has a very > complete collection of DE-9IM cases.
Interesting! Seems exhaustive to me. Two comments: Did you prove exhaustiveness - seems like there should be a way to make a combinatorial argument about how many possible Clementini matrices are possible (9^4 == 6561, less impossible combinations)? Also - it might be easier to do confirm exhaustiveness with simpler shapes, at least for part of the tests. Still, looks great, and comforts me that you are testing that hard. > As was mentioned, you can use the JTS TestBuilder to build and inspect > test cases. You can drag-and-drop Test Suite XML files onto the > TestBuilder, so it's easy to inspect the cases in the XML tests. That is cool! > I'm not sure if Wikipedia would appreciate being flooded with DE-9IM > test cases - it doesn't seem like quite the right place for it. The > Vivid site is a good reference as long as it stays up. I will continue to think about this. I probably don't have time to do fiddle with this in any systematic way, but a table with every possible matrix, a picture, and simple code to generate it might be pretty useful. _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
