r.profile

[Stefan Jaeger]

In article <9503061437.AA20791 at swlab.aben.cornell.edu> you wrote:
: Has anyone found a way to get good values from r.profile?  The problem is
: that the values don't follow the correct order - and for the elevations
: going up a hill, for example, they come out like a sawtooth.  It made me
: very nervous about what was wrong with my elevation map, until I went
: through the grassu archives, and found that this question has been asked
: several times before.  Many people have found the same problem, but unfortuna
tely
: no one seems to have supplied a solution.
 
: I have soil moistures along several transects, and it would be perfect if I
: could output the predictions of the hydrologic model along those same transec
ts
: using r.profile.  The only other idea I have is to MASK the transects and do 
a
: report, and somehow (d.what.rast?) figure out which value is where on the act
ual
: transect.  r.profile looked like the perfect program for my needs, but it
: doesn't seem to be trustworthy.  Oh, I should add that all the transects run
: from southwest to northeast.
 
: Any ideas?  Thanks a million.
 
: Jane Rossing
: jr20 at cornell.edu


Hi Jane,

I have experienced problems with r.profile some months ago and what I
remember was that whatever direction you chose the profile always was going
north-south or vice versa (I can't remeber exactly). You can verify this by
running r.profile with the same coordinates twice, changing the order of the
coordinate pairs. You will find that the output will be the same which is, I
think, not correct. If you have lines changing their direction, the last
point of the first section must be the first of the next section. I have
written a little awk script by that time to give me the correct elevations.
i will e-mail you this script separately if you want to make changes to it.
It will not work for more than two points. Unfortunately I don't have the
time to make any modifications. I have reported the problem to the
bug-report site but never got any response.  
Hope this is of any help!

Stefan

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Stefan Jaeger             |     e-mail: stefan at geo0.geog.uni-heidelberg.de
Dept. of Geography        |         or: ca4 at ix.urz.uni-heidelberg.de
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