Glynn Clements wrote: > In any case, the specific purpose of r.grow.distance is: > > r.grow.distance generates a raster map representing the distance to > the nearest non-null cell in the input map.
It now has an additional function: to generate a raster map containing the value of the nearest cell. >From this, it is possible to mimic the behaviour of r.grow, but substantially faster, with e.g.: # equivalent to: r.grow input=$inmap output=$outmap radius=$radius metric=$metric temp=r.grow.tmp.$$ r.grow.distance in=$inmap distance=$temp.dist value=$temp.near metric=$metric r.mapcalc "$outmap = if($temp.dist < $radius,$temp.near,null())" r.colors $outmap rast=$temp.near g.remove rast=$temp.dist,$temp.near Whereas the worst-case time taken by r.grow is proportional to the square of the buffer radius, the above is proportional only to the area of the map, regardless of the buffer radius. I'll replace r.grow in 7.0 with a script along these lines. -- Glynn Clements <[EMAIL PROTECTED]> _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
