compute agrid in two passes to allow for 3x3, 5x5 etc
compute agrid in two passes to allow for 3x3, 5x5 etc

gpac/gpac,rbouqueau/gpac,gpac/gpac,rbouqueau/gpac,gpac/gpac,gpac/gpac,rbouqueau/gpac,rbouqueau/gpac,gpac/gpac,gpac/gpac,rbouqueau/gpac,rbouqueau/gpac,rbouqueau/gpac,rbouqueau/gpac,gpac/gpac,gpac/gpac