[GRASSLIST:4342] big colr files

tatel at euskalnet.net tatel at euskalnet.net
Mon Sep 13 15:10:02 EDT 2004

Hi all

This is probably somewhat dumb question, but after a search on mailing
list archives, I still can't find a fix, only some headings about
problems with r.patch an color files. Hope some of you can help.

I'm working on a big region (500 x 250 Kms). To cover it, I have
imported some 10000 x 10000 rows/columns tiles from a mrsid mosaic

Now I would to make a grid of "cells" at 15 m resolution. Each cell has
10Km side  So I made a scritp to test if a cell is fully into one of
these big tiles. If it is, I get the cell using r.mapcalc with no problems.

If the cell needs more than one big tile to be completed, I'm using
r.patch to get it. I noticed that making support files was sometimes
slow. In such cases, displaying the cell can take from 4 to 20 seconds,
while most of the cells are displayed instantly. The only difference I
can find is in the colr file, wich is bigger (about 200 K ) than the
others (about 32 K). So there are much more colors(?) This is not true
in all cases where r.patch was used.

What could I do in order to get faster display of these problematic
files? I'm using 5.3 from CVS. The build is maybe 2 months old. Would an
upgrade get this corrected?

Thanks a lot,


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