I'm trying to calculate a new field from existing fields based on a simple expression for a set of polygons in GDAL/OGR.
The expression is basically:
new field = (field 1 / field 2) * field 3
After calculating, I need to append the new field on to the existing set of polygons and sum all the values in that new field.
This is very straightforward in ArcGIS or using ArcPy, but I can't find a solution for GDAL/OGR.