When you get this all working, please post a description of the final outcome in the grass wiki. Thanks, Jerry
---- Original message ---- >Date: Wed, 19 Dec 2007 15:16:10 +0200 >From: Craig Leat <[EMAIL PROTECTED]> >Subject: Re: [GRASS-user] Working with a large number of maps >To: Glynn Clements <[EMAIL PROTECTED]> >Cc: [email protected] > >Glynn Clements wrote: >> Craig Leat wrote: >> >>> I have 139 high resolution images, which I need to use as a background map >>> for some digitizing work. >>> >> How do the individual maps relate to the overall region? >> >> If they are (approximately) tiles, I would suggest using a >> hierarchical approach, patching groups of adjacent tiles into larger >> tiles, then patching the larger tiles together, so that each r.patch >> operation has relatively few maps, and the earlier stages have >> relatively small regions. >> >> The total time taken by r.patch is roughly proportional to the total >> number of cells in the region multiplied by the number of input maps, >> so the combination of a large region and a large number of maps will >> be slow. >> >> >Thanks for the advice Glynn. The images are tiles and the filenames >follow a regular pattern, so I am able to patch blocks together quite >easily with a simple script. I included lots of echos in the script and >now I even have verbose messages ;-) > >The script is running right now and making good progress... > >Craig >_______________________________________________ >grass-user mailing list >[email protected] >http://lists.osgeo.org/mailman/listinfo/grass-user Gerald Nelson Professor, Dept. of Agricultural and Consumer Economics University of Illinois, Urbana-Champaign office: 217-333-6465 cell: 217-390-7888 315 Mumford Hall 1301 W. Gregory Urbana, IL 61801 _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
