Re: [GRASS-user] looping r.mapcalc in a shell script
Hi Rajat,
If you send me your two files I can send you a line of code that should work.
In this case I will need to know if you work with GRASS 6 or 7 and your
operating system...
Cheers
Stefan
From: Rajat Nayak [mailto:rajat27...@gmail.com]
Sent: 4. april 2014 04:47
To: Blumentrath, Stefan
Subject: Re: [GRASS-user] looping r.mapcalc in a shell script
Thank you Stefan for your reply.
One of the problems I'm facing with all the suggested codes is, the code is
unable to find either of the file lists.
Both the filelists were created using g.mlist command, it it worked fine with
other loops like reclass.
I will work again on your suggested line of thoughts, and hope will be able to
crack it.
Regards
Rajat
Rajat Nayak
On Thu, Apr 3, 2014 at 5:38 PM, Blumentrath, Stefan
stefan.blumentr...@nina.nomailto:stefan.blumentr...@nina.no wrote:
You could also combine your two lists using the paste command, then awk in
order to create proper map calculator expressions, which you then can send to
the map calculator through xargs.
That way you could process the maps in parallel (if you are on a 64bit system
with multi cores)...
Something like (would likely require some adjustments, e.g. regarding field
delimiters):
paste NDVIFILES VIQALIST | awk '{print \ $1 _MASK=$1 ' * $2 \}' | xargs
-P 4 r.mapcalc {}
Cheers
Stefan
-Original Message-
From:
grass-user-boun...@lists.osgeo.orgmailto:grass-user-boun...@lists.osgeo.org
[mailto:grass-user-boun...@lists.osgeo.orgmailto:grass-user-boun...@lists.osgeo.org]
On Behalf Of rajatrn
Sent: 3. april 2014 10:31
To: grass-user@lists.osgeo.orgmailto:grass-user@lists.osgeo.org
Subject: [GRASS-user] looping r.mapcalc in a shell script
Hi,
I have two layer lists, NDVIFILES and VIQALIST, both developed using g.mlist
command in GRASS.
Each file has 22 items in it. I would like to perform a simple raster
calculation of the following form, Mask$NDVIFILES [i] = NDVIFILES[i] *
VIQALIST[i] I'm unable to create a loop which can sequentially produce the
required outputs.
I will be grateful if anyone can help me with creating a loop using bash/shell
script.
I know it is simpler to do it in R but will be great if can be implemented on
using grass terminal/shell.
Thank you in advance,
Sincerely,
Rajat
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[GRASS-user] i.pca gives error
Hi list, i am processing plenty of modis subsets into a group called pca when using WinGRASS it gives an error GRASS 7.0.svn i.pca --overwrite input=pca output_prefix=_msub Computing covariance matrix... 100% ERROR: No non-null values GRASS 7.0.svn can anybody help please? Martin ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] i.pca gives error
that helps but it breaks there... GRASS 7.0.svn i.pca --overwrite input=pca output_prefix=_msub Computing covariance matrix... 100% Calculating principal components... 100% Rescaling to range 0,255... 100% Eigen values, (vectors), and [percent importance]: GRASS 7.0.svn On Fri, Apr 4, 2014 at 5:44 PM, Markus Neteler nete...@osgeo.org wrote: On Fri, Apr 4, 2014 at 1:47 PM, Martin van Brakel m.l.vanbra...@gmail.com wrote: Hi list, i am processing plenty of modis subsets into a group called pca when using WinGRASS it gives an error GRASS 7.0.svn i.pca --overwrite input=pca output_prefix=_msub Computing covariance matrix... 100% ERROR: No non-null values GRASS 7.0.svn Did you set the computational region to the map beforehand? g.region rast=pca -p then i.pca ... See also: http://grasswiki.osgeo.org/wiki/Computational_region Since we currently have issues on the server (slow), see also the wiki mirror at: http://grass.fsv.cvut.cz/wiki-mirror/index.php/Computational_region hope this helps Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] i.pca gives error
On Fri, Apr 4, 2014 at 2:43 PM, Martin van Brakel m.l.vanbra...@gmail.com wrote: that helps but it breaks there... GRASS 7.0.svn i.pca --overwrite input=pca output_prefix=_msub Computing covariance matrix... 100% Calculating principal components... 100% Rescaling to range 0,255... 100% Eigen values, (vectors), and [percent importance]: GRASS 7.0.svn Please try (just for fun) to not use the leading _ in the prefix parameter. Please also post the output of g.version -g Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] calculation valley floor width in GRASS or some index indicating valley floor width?
On Tue, 1 Apr 2014 00:52:53 -0700 (PDT) Helmut Kudrnovsky hel...@web.de wrote: hi, any hint or pointer to some grass gis procedure/literature/web link/etc how to caculate valley floor width in GRASS or some index indicating valley floor width. the idea is to get some measure how wide or narrow a valley is. thanks in advance! That is a very involved question, starting with how you define the valley floor quantitatively to begin with. You could calculate an index of concavity or average slope and plot the point where the measure (e.g. concavity of slope, or average slope) drops below a certain value that would be a valley floor boundary by definition. There should be several grass tools that could be applied. JWDougherty ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] calculation valley floor width in GRASS or some index indicating valley floor width?
Helmut wrote: any hint or pointer to some grass gis procedure/literature/web link/etc how to caculate valley floor width in GRASS or some index indicating valley floor width. the idea is to get some measure how wide or narrow a valley is. JWDougherty wrote: That is a very involved question, starting with how you define the valley floor quantitatively to begin with. You could calculate an index of concavity or average slope and plot the point where the measure (e.g. concavity of slope, or average slope) drops below a certain value that would be a valley floor boundary by definition. There should be several grass tools that could be applied. e.g. run 'r.param.scale param=feature' to pull out channels, then r.watershed to make a rivers map and r.cost to calculate distance from the center-line (rivers) to the edge of the valley. Of course rivers are not always in the center of the valley, perhaps take the r.param.scale valleys and run r.cost to find the cost to the middle. Then extract the 'ridge lines' of the distance-cost map, again with r.param.scale, and double the peak values along the ridge. It is very similar to the classic 'river mile' problem, to define well a line down the center of the channel when nature isn't as simple as a pipe and valleys merge, islands happen, etc. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
