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<p>Hi Mira,</p>
<p>I find a more elegant way to create a mask from an arbitrarily
long list of raster categories would be to use r.reclass where you
can use an input file:</p>
<p>r.reclass input=subcatchments output=MASK rules=mask.dat</p>
<p>and in mask.dat you list your categories:</p>
<pre>12=1
23=1
10=1
...
1200=1
</pre>
<p>Might help, although the problem seems to have been solved.</p>
<p>Michel<br>
</p>
<div class="moz-cite-prefix">On 04/05/2017 03:59 PM, Mira Kattwinkel
wrote:<br>
</div>
<blockquote
cite="mid:9a045c30-7b90-0df0-f30a-787f2a50e067@uni-landau.de"
type="cite">Dear Micha
<br>
<br>
thanks for your suggestion.
<br>
<br>
Actually, that's is what I usually do. However, I am not really
interested in the catchment of the endpoints of the edges but in
sampling points lying at the streams. If a point lies within the
dem cell of the outlet, which can be a confluence of two streams,
the coordinate approach will result in the catchment of both
confluences, although the point lies just at one of them. That's
why I came up with the idea of summing up the subcatchments of
only the relevant branch of the stream network.
<br>
<br>
Maybe there are other thoughts on that?
<br>
<br>
Mira
<br>
<br>
<br>
On 05/04/17 15:25, Micha Silver wrote:
<br>
<blockquote type="cite">
<br>
<br>
<br>
On 04/05/2017 03:22 PM, Mira Kattwinkel wrote:
<br>
<blockquote type="cite">Dear List,
<br>
<br>
I am using r.mask to create a new raster map that only
contains certain categories given in 'maskcats'. Then, I use
r.mapcalc to save the map under a new name and (to be on the
save side) delete the MASK with r.mask flag '-r'. I do this in
a loop and it works fine until a case when the number of
categories to combine is 213 (trail and error lead to 106 as
the maximum number that works fine). Flag 'verbose' gives the
message that a MASK was created, but none is there. The
problem arises in both cases when I directly use Grass or
through R using execGrass.
<br>
<br>
Is there a limit in the number of categories that can be
passed to r.mask? I did not find any hint about that.
Additionally, I wonder why there is no error message but in
the contrary one that tells me that a MASK was created even
when it failed.
<br>
<br>
In case the details are important (or if anybody has a better
idea how to achieve what I want): I have a raster map of
subcatchemts belonging to stream segments created with
r.stream.basins. For the endpoints of segments, I want to
combine these subcatchments to a total catchment raster map
containing all upstream catchments.
<br>
<br>
</blockquote>
If you have the endpoint of of the outlet segment, you might use
that as the "coordinates" parameter to r.stream.basins to create
a single large drainage basin. Then use that as the mask to get
out the subcatchments.
<br>
<br>
<blockquote type="cite">Thanks a lot,
<br>
<br>
Mira
<br>
<br>
<br>
</blockquote>
<br>
-- <br>
Micha Silver
<br>
cell: +972-523-665918
<br>
</blockquote>
<br>
</blockquote>
<br>
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