[GRASS-user] DEMs not reporting elevation

[John C. Tull]

Markus,

Thanks for that advice. The problem is solved. So, for the record, if  
you are working with a region that is larger than the raster, but  
includes the raster, will the problems I was having occur?

Cheers,
John

On Jul 24, 2007, at 1:32 AM, Markus Neteler wrote:

> John,
>
> did you run
>
> g.region rast=demmap -p
> first? You have to set the current region to the map (or spatial  
> subset) to
> work with it.
>
> Markus
>
> John C. Tull wrote on 07/24/2007 07:19 AM:
>> I have been having no luck today working with DEMs in GRASS. I have
>> tried several sources for DEM data derived from 24k quads. I can  
>> bring
>> in the dem and it will draw with color as expected. If I query the
>> map, I do not get elevation:
>> 449208.962656|4171350.10373||*
>>
>> If I try to produce a hillshade from the map, it is blank. This is
>> making me a bit insane because I have done these things before  
>> without
>> issue. I have no problem using the dem in the spearfish dataset.
>>
>> I am unable to get things working using a 24k dem from:
>> ftp://nas.library.unr.edu/keck/30mDEM/30mdemzip/quad1113.zip
>>
>> After renaming the .dem file to alcatraz_island (although I also  
>> tried
>> using a NED file in another format with no name changes), I ran:
>> r.in.gdal input=alcatraz_island.dem output=alcatraz_island_dem
>>
>> The colors are there in my region and can be changed with r.colors as
>> expected, but I still have nothing returned on query. I am trying to
>> use r.mapcalc or r.recode to derive a band along a contour, but I  
>> only
>> get empty files returned. Is there something simple I am overlooking.
>>
>> This happens with both 6.2.2 and 6.3cvs.
>>
>> Thanks,
>> John Tull
>
>
> ------------------
> ITC -> dall'1 marzo 2007 Fondazione Bruno Kessler
> ITC -> since 1 March 2007 Fondazione Bruno Kessler
> ------------------
>
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