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SUBMIT YOUR IDEAHere's my solution. Had a lot of fun playing with various sorts on the final data set, trying to figure out how to match the image (area, min X, min Y in ascending and descending order). Came up with some interesting patterns, especially the last two which are sorted on area in ascending and descending order. But I couldn't find the sort order that matched the image.
Also learned a few interesting things looking at the solution:
@garthn555 wrote:The extra 21 objects (537-516) seem to be true triangles - the nulls are lines. (I added collinear test records to check). So does that mean if 3 collinear points are used in st_createpolygon that it won't produce a spatial object?
Yes, 3 perfectly collinear spatial points will yield "ST_CreatePolygon: Failed to form valid polygon."
That being said, the issue with this scenario is introduced by the Make Grid tool and the issues of plotting a flat plane to a curved surface. The grid points are not technically collinear, but practically they are, and therein lies the issue.
I was stuck for the longest time at 540 triangles before I peeked at the solution to see that the area tolerance was set to > .1 sq miles.
My solution: