[GRASS-user] problems using r.proj with large data set

[Gerald Nelson]

I was able to use gdalwarp successfully. I exported the file as a geotiff, warped it and then imported the new geotif. Thanks for the tip on that. Whoever came up with the names for the options was not into readability! Is there any possibility that r.proj could become a front end for gdalwarp; essentially doing the steps I did manually behind the scenes?

Thanks, Jerry

---- Original message ----
>Date: Fri, 8 Dec 2006 02:09:28 +0000
>From: Glynn Clements <glynn at gclements.plus.com>  
>Subject: Re: [GRASS-user] problems using r.proj with large data set  
>To: Maciej Sieczka <tutey at o2.pl>
>Cc: JerryNelson <gnelson at uiuc.edu>, grassuser at grass.itc.it, grass-dev at grass.itc.it
>
>
>[CC'd to grass-dev]
>
>Maciej Sieczka wrote:
>
>> > Is this a problem with large files that I will just have to work around or
>> > is it something to do with my setup?
>> 
>> Propably the same, very old issue:
>> http://intevation.de/rt/webrt?serial_num=241
>
>I looked into this a while ago. Unfortunately, you can't use rowio (or
>a home-grown equivalent), as libgis doesn't allow the projection to be
>changed while maps are open. So, you have to read the entire input
>map, close it, change the projection, then write the output map.
>
>To get around the memory issues, you would first need to copy the
>relevant portion of the input map to a temporary file, then use a
>cache backed by that file.
>
>The segment library would do the job, although it could add a
>significant performance overhead.
>
>-- 
>Glynn Clements <glynn at gclements.plus.com>
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