1Centroid - polygonM (problem case - GEOS throws away the M coordinates)
2:memory: #use in-memory database
3SELECT astext(centroid(geomFromText('POLYGONM((0 0 1, 0 2 1, 2 2 1, 2 0 1, 0 0 1))')))
41 # rows (not including the header row)
51 # columns
6astext(centroid(geomFromText('POLYGONM((0 0 1, 0 2 1, 2 2 1, 2 0 1, 0 0 1))')))
7POINT(1 1)
8
9