Jonathan Greenberg wrote: > Thanks, but I'm more curious in just the generic way GRASS does > tiled processing (say, in mapcalc). I assume there is a low-level > processing layer GRASS uses (or no?).
GRASS' primary raster processing model is row-by-row. Where possible, the code reads a row, processes it, writes a row. If a neighbourhood is required, the code typically maintains a scrolling window; it may use the rowio library for this, or do it itself (r.mapcalc uses rowio). Modules which need uncorrelated access either read the entire map into RAM, or use an uncompressed temporary file which may be a simple 2D array or may be tiled. If it's tiled, the code may use the segment library, or do it itself. -- Glynn Clements <gl...@gclements.plus.com> _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
