Re: [GRASS-user] unstable results with r.param.scale ?
Thank you Vincent & Vincent. I managed to reproduce an issue with curvature tool – output result differs significantly by each run. You can track progress in GitHub issue tracker: https://github.com/OSGeo/grass/issues/1168 In the mean time just disable OpenMP before running r.param.scale: export OMP_NUM_THREADS=1 Māris. ___ grass-user mailing list grass-user@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] unstable results with r.param.scale ?
Hi Māris, Here is the region information : g.region -p projection: 1 (UTM) zone: 10 datum: nad83 ellipsoid: grs80 north: 4009245.5 south: 4008455.5 west: 684018.58 east: 685270.58 nsres: 1 ewres: 1 rows: 790 cols: 1252 cells: 989080 GRASS installed from ubuntugis-unstable (focal). Following Vincent's feedback I will look into the compilation options used. Best, Vincent Le 09/12/2020 à 14:25, Maris Nartiss a écrit : Please state your computation region settings. This seems like a overflow / memory corruption and region settings might play a role here. Māris. -- Vincent Godard CEREGE, OSU Pythéas Aix-Marseille Université Europôle Méditerranéen de l’Arbois - BP 80 13545 Aix-en-Provence cedex 04, France god...@cerege.fr ___ grass-user mailing list grass-user@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] unstable results with r.param.scale ?
Don't have time right now, but running it with valgrind might show the
problem.
Anna
On Wed, Dec 9, 2020 at 8:27 AM Vincent Bain wrote:
> Hello Vincent,
>
> in case it could be related to my recent issue with r.param.scale:
>
> https://lists.osgeo.org/pipermail/grass-user/2020-October/081788.html
>
> In my case there was most probably something wrong with my OpenMP
> configuration.
>
> HTH,
> Vincent.
>
> Le mercredi 09 décembre 2020 à 13:59 +0100, Vincent Godard a écrit :
> > Dear Grass users,
> >
> > I've been using r.param.scale to compute various type of curvatures
> > over
> > a 1 m LiDAR DEM (FCELL) (from opentopography.org) :
> >
> > r.param.scale --o -c input=dem output=curvature size=15 method=profc
> > r.info -r curvature
> >
> > I usually get reasonable results like (checked with independent
> > calculations) :
> >
> > min=-0.203124601340989
> > max=0.0685868278408049
> >
> > But when running this command repeatedly, I randomly (usually every
> > 3rd
> > or 4th time) get very different results like :
> >
> > min=-127112309.998249
> > max=131128979.492382
> >
> > I am running GRASS 7.8.4 on Ubuntu 20.04. The problem is also
> > present
> > when running r.param.scale from QGIS or rgrass7 (in a R session).
> >
> > I have replicated the problem with another high resolution DEM of
> > different source (still FCELL), and also with a 30 m SRTM DEM
> > (CELL),
> > but in this case the occurrence of these odd results is less
> > frequent
> > and they are not contrasting as much with the expected outcome
> > ("only"
> > by a 1 or 2 order of magnitude). The problem is present with or
> > without
> > the -c option, and seems only to affect the computation of
> > curvatures
> > (profc,planc,longc,crosc,minic,maxic).
> >
> > Has anyone encountered something like that, or have any idea about
> > what
> > might be going on?
> >
> > Thanks in advance,
> >
> > Vincent
> >
>
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Re: [GRASS-user] unstable results with r.param.scale ?
Hello Vincent,
in case it could be related to my recent issue with r.param.scale:
https://lists.osgeo.org/pipermail/grass-user/2020-October/081788.html
In my case there was most probably something wrong with my OpenMP
configuration.
HTH,
Vincent.
Le mercredi 09 décembre 2020 à 13:59 +0100, Vincent Godard a écrit :
> Dear Grass users,
>
> I've been using r.param.scale to compute various type of curvatures
> over
> a 1 m LiDAR DEM (FCELL) (from opentopography.org) :
>
> r.param.scale --o -c input=dem output=curvature size=15 method=profc
> r.info -r curvature
>
> I usually get reasonable results like (checked with independent
> calculations) :
>
> min=-0.203124601340989
> max=0.0685868278408049
>
> But when running this command repeatedly, I randomly (usually every
> 3rd
> or 4th time) get very different results like :
>
> min=-127112309.998249
> max=131128979.492382
>
> I am running GRASS 7.8.4 on Ubuntu 20.04. The problem is also
> present
> when running r.param.scale from QGIS or rgrass7 (in a R session).
>
> I have replicated the problem with another high resolution DEM of
> different source (still FCELL), and also with a 30 m SRTM DEM
> (CELL),
> but in this case the occurrence of these odd results is less
> frequent
> and they are not contrasting as much with the expected outcome
> ("only"
> by a 1 or 2 order of magnitude). The problem is present with or
> without
> the -c option, and seems only to affect the computation of
> curvatures
> (profc,planc,longc,crosc,minic,maxic).
>
> Has anyone encountered something like that, or have any idea about
> what
> might be going on?
>
> Thanks in advance,
>
> Vincent
>
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Re: [GRASS-user] unstable results with r.param.scale ?
Please state your computation region settings. This seems like a overflow / memory corruption and region settings might play a role here. Māris. ___ grass-user mailing list grass-user@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] unstable results with r.param.scale ?
Dear Grass users,
I've been using r.param.scale to compute various type of curvatures over
a 1 m LiDAR DEM (FCELL) (from opentopography.org) :
r.param.scale --o -c input=dem output=curvature size=15 method=profc
r.info -r curvature
I usually get reasonable results like (checked with independent
calculations) :
min=-0.203124601340989
max=0.0685868278408049
But when running this command repeatedly, I randomly (usually every 3rd
or 4th time) get very different results like :
min=-127112309.998249
max=131128979.492382
I am running GRASS 7.8.4 on Ubuntu 20.04. The problem is also present
when running r.param.scale from QGIS or rgrass7 (in a R session).
I have replicated the problem with another high resolution DEM of
different source (still FCELL), and also with a 30 m SRTM DEM (CELL),
but in this case the occurrence of these odd results is less frequent
and they are not contrasting as much with the expected outcome ("only"
by a 1 or 2 order of magnitude). The problem is present with or without
the -c option, and seems only to affect the computation of curvatures
(profc,planc,longc,crosc,minic,maxic).
Has anyone encountered something like that, or have any idea about what
might be going on?
Thanks in advance,
Vincent
--
Vincent Godard
CEREGE, OSU Pythéas
Aix-Marseille Université
Europôle Méditerranéen de l’Arbois - BP 80
13545 Aix-en-Provence cedex 04, France
god...@cerege.fr
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