Hi, Just saw this on slashgeo.org, http://www.geovista.psu.edu/sites/geocomp99/Gc99/076/gc_076.htm from a superficial look at the rotated squares and map of China I'd say GRASS's v.to.rast & r.in.poly do a better job, but it would be interesting for someone to run some trials and see how we stack up. Hamish