stephen sefick wrote: > ERROR: G_malloc: unable to allocate 18446744072071437530 > bytes of memory at > read_map.c:38 It wants 1.84e+10 gigabytes of RAM to do the job. check that your region settings have not gone bigger than say 40000x40000 rows & columns with 'g.region -p' probably running this before r.fillnulls helps: g.region rast=inputmap Hamish