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Sat Mar 6 23:29:49 EST 1993

Newsgroups: info.grass.user
From: shapiro at (Michael Shapiro)
Subject: Re: dem extraction & examine
Message-ID: <C3I4Ho.8st at>
Sender: news at (Net.Noise owner)
Organization: US Army Corps of Engineers Construction Engineering Research Labs
References: <9302191938.AA02409 at>
Date: Sun, 7 Mar 1993 04:29:48 GMT
Lines: 65

In <9302191938.AA02409 at> riker at (Dan Riker) writes:

m.dem.extract has been worked on a lot. The problems are not GRASS vs
sparc stations, but partly due to the variability in the DEM format
supplied by USGS. The new m.dem.extract (on the moon and in 4.1)
tries to be more flexible about the USGS "formats" as well as allowing
for input from disk files. Note that this program only expects DEM
data, but USGS will distribute tapes that have both DEM and DLG data,
and some of the DEM formats are incorrect. The DLG data must be
eliminated when copying to disk, but some of the DEM format problems
m.dem.extract can work around. But, note, this is not true of
m.dem.examine, which was retained unaltered. You can run an
examine using m.dem.extract (newer version) by simply not specifying an
output layer.

>Hello there, I hope you all are doing well.

>I am still having problems reading in my dems.  This is the output from the command m.dem.examine. Note the resolution (0)

>min elevation: 224.000000  max elevation: 2816.000000

>ns_res: 0.000000  ew_res: 0.000000
># of columns in file =   809773872

>file north UTM = 4136628.750000
>file south UTM = 4122665.750000
>file east UTM = 577600.937500
>file west UTM = 566405.250000

>This is the outcome of the command m.dem.extract (using an exabyte tape, but the same shows for the 1/2 inch tape):
>enter option > 1024

>You have chosen:
>  blocksize=1024
>Is this correct? (y/n) [y] 
>Current Window Settings-----------------------------
>rows:       1173
>cols:       1167
>north:      4130200.000000
>south:      4095000.000000
>east:       590000.000000
>west:       555000.000000
>ns_res:     30.008525
>ew_res:     29.991431

>Reading Elevation Tape...     
>ERROR: error reading tape
>Mapset <PERMANENT> in Location <california>
>GRASS 4.0 >  

>Does anyone have an idea about what is going on here?  I have heard rumors recently that GRASS and Sun Sparcstations don't get along.  Is that the problem?
>I would sincerely appreciate any help on these matters.


Michael Shapiro U.S. Army CERL
Environmental Division       

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