[GRASSLIST:2710] Re: stitching geotiffs

[Richard Greenwood]

Martin du Saire wrote:
> At 03:38 PM 2/20/2004 -0700, you wrote:
> 
>> Martin du Saire wrote:
>>
>>> Outstanding!  Thank you Richard and  Glynn.  I think I may eventually 
>>> have to r.patch the individual maps.  I was playing around with two 
>>> maps within a single zone, and the r.stats -a -n map1,map2 output did 
>>> not reflect what I expected to be the composite of the two (Actually, 
>>> the numbers made no sense at all).  One last question:
>>> Without having specific datum in my adjacent zones (14, 16), is there 
>>> some way to make upper-bound estimates on the amount of distortion 
>>> resulting from the r.proj method=nearest (the maps are land-use/cover)?
>>> Thanks again.
>>> Martin
>>
>>
>> That's a hard question that I will not try to answer directly. Map 
>> distortion can involve linear, directional, and/or area distortion. So 
>> first you 
> 
> 
> 
> Thanks again.
> 
> Having a little trouble with r.proj though:
> 
> ERROR> Input map is outside current region


You are on the right track - enlarge your region to encompass the area 
of the maps that you are bringing in. And then set your current region 
to your default region (g.region 1). Remember that GRASS only works 
within the bounds of your current region, is if you had zoomed into an 
area, that's the only area in the target location, that would be the 
only area that would be processed with most GRASS commands.

Rich

-- 
Richard Greenwood
www.greenwoodmap.com