Re: [GRASS-user] DTM with contour lines and points
Il 20/04/2012 00:51, Pedro Venâncio ha scritto: I thought a way to get around, which is to convert the contours to equally spaced points and join these points whith the elevation points layer. Is there a more correct and straightforward way to do? your real data are vertices anyway, so I think extracting them and patching them with points is the straightforward way. All the best. -- Paolo Cavallini See: http://www.faunalia.it/pc ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.stream.extract: map mis-match error
On Thu, Apr 19, 2012 at 10:57 PM, Rich Shepard rshep...@appl-ecosys.com wrote: On one project the r.stream.extract error, Accumulation map does not match elevation map!, was caused by a mask on the elevation map. With this project the mask was removed, and no longer limits the DEM region. It is perfectly ok to set the region to a subregion of the DEM and to set a MASK. These settings should not be modified, however. As long as r.watershed and r.stream.extract are used on the same region settings and the same MASK, the map mismatch error should not happen. Just in case, masking should be done by creating a MASK, not by modifying the elevation values. I started over to ensure the elevation map was not masked. Because of the large size, I used the NHD basin map's region to set the analytical region: g.region vect=basins align=dem_proj Then changed resolution from 1 US Foot (0.305m) to 10m (30 US Feet). In your last posts you were using a resolution of 30m? This is the same region and elevation map used in the process leading to application of the r.stream.extract module, the accumulation map was generated by r.watershed, and r.stream.extract has no problem running with the unweighted accumulation map. Therefore, I assume the error arose in the calculation of weight or applying that weight to the unweighted accumulation map. But in your last posts, applying the weight worked fine (map1.pdf, map2.pdf, map3.pdf)? The weighed accumulation map seemed to produce the best results. BTW, the vector output of r.stream.extract would have been easier to see on the screenshots. If this assumption is correct, where do I look to find how to resolve the problem? Try to set the region and MASK before the analysis, then don't modify these settings during the analysis. Something like g.region vect=basins align=dem_proj g.region res=10m -a r.resamp.stats in=dem_proj out=dem_10m method=average -w v.to.rast in=basins out=MASK type=area use=val val=1 r.watershed elevation=dem_10m acc=dem_10m.acc basin=dem_10m.basin threshold=15 r.mapcalc dem_10m.acc.w = dem_10m.acc * weight r.stream.extract elevation=dem_10m acc=dem_10m.acc.w stream_rast=dem_10m.streams stream_vect=dem_10m_streams threshold=??? You may need to try different values for threshold with r.stream.extract in order to get the desired detail. HTH, Markus M ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Re: internal buffer of polygon
Another workaround. Don't know if that helps and never tried it out, but my approach for inner offset would be a decomposition of the polygons: v.type in=poly out=poly_as_line type=boundary,line v.parallel v.clean tool=break v.type type=line,boundary v.centroids v.build If you can not define the side-paramter of v.parallel (is it always the same?), you might want to create parallels and polygons for both sides and remove the outer by querying if the original polygon lies inside, e.g. if the perimeter-lenth is longer than the original one greetz, patrick On Thu, Oct 29, 2009 at 4:59 PM, Milton Cezar Ribeiro miltinho.astrona...@gmail.com wrote: Hi Maning, Sometimes I have the same issue, but I don't solve this on vector. Just supose you have a map where 1 is your raster-based-polygon and NULL is outside of polygon. You can use r.mapcalc to invert it, in the maner that 1 come to be your non-polygon, and NULL your polygon. So you can run r.buffer with positive value and at the end may be you need to do some kind of crossing between original and output maps. Bests. miltinho 2009/10/29 maning sambaleemmanuel.samb...@gmail.com I tried using a negative values as buffer=-3000 in v.buffer but it doesn't give me internal buffer in a polygon layer. Any hints? -- cheers, maning ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] GRASS module (python, gparser): Set a tick for flag by default
Hi, I am working on a python script which involves a g.parser module (to get the input mask for a module as for other modules in GRASS). So far I know how a flag is produced in the beginning of the script. E.g.: #%Flag #% key: f #% description: My Flag of Interest #%end Is there any possibility to set the flag ticked by default? So like providing an answer for options. Best regards, Johannes -- NEU: FreePhone 3-fach-Flat mit kostenlosem Smartphone! Jetzt informieren: http://mobile.1und1.de/?ac=OM.PW.PW003K20328T7073a ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] GRASS module (python, gparser): Set a tick for flag by default
Johannes Radinger wrote: I am working on a python script which involves a g.parser module (to get the input mask for a module as for other modules in GRASS). So far I know how a flag is produced in the beginning of the script. E.g.: #%Flag #% key: f #% description: My Flag of Interest #%end Is there any possibility to set the flag ticked by default? So like providing an answer for options. No. Unlike options, where the user can override a default by providing an explicit value, there's no way to disable a flag which is enabled by default, and no way to specify GUI behaviour distinct from command-line behaviour, so flags always default to false. The only option is to invert the sense of the flag, i.e. enable the behaviour by default and provide a don't ... flag to disable the behaviour. -- Glynn Clements gl...@gclements.plus.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] vector import issues v.in.ogr
Hi Pankaj, What format are you exporting to? The vectors in india_basins_vector.png look good. Daniel -- B.Sc. Daniel Lee Geschäftsführung für Forschung und Entwicklung ISIS - International Solar Information Solutions GbR Vertreten durch: Daniel Lee, Nepomuk Reinhard und Nils Räder Softwarecenter 3 35037 Marburg Festnetz: +49 6421 379 6256 Mobil: +49 176 6127 7269 E-Mail: l...@isi-solutions.org Web: http://www.isi-solutions.org Am 20. April 2012 11:16 schrieb Pankaj Kr Sharma pks...@gmail.com: I am using latest grass v7 svn. Today, I created a vector map by patching some raster and converting it to vector. Thereafter, I exported it and then imported it back. However, in the imported vector, some polygons are missing. The centroid is visible, but the polygon is missing. What could be the reason. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] vector import issues v.in.ogr
I created this vector by r.to.vect command. Then, I ran v.out.ogr. And, thereafter I tried v.in.ogr. Which resulted in erroneous vector. On Fri, Apr 20, 2012 at 4:31 PM, Daniel Lee l...@isi-solutions.org wrote: Hi Pankaj, What format are you exporting to? The vectors in india_basins_vector.png look good. Daniel -- B.Sc. Daniel Lee Geschäftsführung für Forschung und Entwicklung ISIS - International Solar Information Solutions GbR Vertreten durch: Daniel Lee, Nepomuk Reinhard und Nils Räder Softwarecenter 3 35037 Marburg Festnetz: +49 6421 379 6256 Mobil: +49 176 6127 7269 E-Mail: l...@isi-solutions.org Web: http://www.isi-solutions.org Am 20. April 2012 11:16 schrieb Pankaj Kr Sharma pks...@gmail.com: I am using latest grass v7 svn. Today, I created a vector map by patching some raster and converting it to vector. Thereafter, I exported it and then imported it back. However, in the imported vector, some polygons are missing. The centroid is visible, but the polygon is missing. What could be the reason. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] GRASS module (python, gparser): Set a tick for flag by default
Thank you. Good to know that, so that I'll do a reverse of the meaning of the flag as you mentioned (...don't...). cheers, Johannes Original-Nachricht Datum: Fri, 20 Apr 2012 11:26:55 +0100 Von: Glynn Clements gl...@gclements.plus.com An: Johannes Radinger jradin...@gmx.at CC: grass user list grass-user@lists.osgeo.org Betreff: Re: [GRASS-user] GRASS module (python, gparser): Set a tick for flag by default Johannes Radinger wrote: I am working on a python script which involves a g.parser module (to get the input mask for a module as for other modules in GRASS). So far I know how a flag is produced in the beginning of the script. E.g.: #%Flag #% key: f #% description: My Flag of Interest #%end Is there any possibility to set the flag ticked by default? So like providing an answer for options. No. Unlike options, where the user can override a default by providing an explicit value, there's no way to disable a flag which is enabled by default, and no way to specify GUI behaviour distinct from command-line behaviour, so flags always default to false. The only option is to invert the sense of the flag, i.e. enable the behaviour by default and provide a don't ... flag to disable the behaviour. -- Glynn Clements gl...@gclements.plus.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user -- NEU: FreePhone 3-fach-Flat mit kostenlosem Smartphone! Jetzt informieren: http://mobile.1und1.de/?ac=OM.PW.PW003K20328T7073a ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.stream.extract: map mis-match error
On Fri, 20 Apr 2012, Markus Metz wrote: It is perfectly ok to set the region to a subregion of the DEM and to set a MASK. These settings should not be modified, however. As long as r.watershed and r.stream.extract are used on the same region settings and the same MASK, the map mismatch error should not happen. Just in case, masking should be done by creating a MASK, not by modifying the elevation values. Markus, For the current there is no mask and the region is set to the same parameters before the model is run. That's why I cannot find the source of the error. In your last posts you were using a resolution of 30m? No. The location units are US Feet so g.region reports them as 30. That's approximately 10m and I use the latter as a descriptor. The original DEM has a cell size of 1 x 1 feet (0.305 x 0.305 m) and is much too large to process on a system with 4G RAM. But in your last posts, applying the weight worked fine (map1.pdf, map2.pdf, map3.pdf)? The weighed accumulation map seemed to produce the best results. BTW, the vector output of r.stream.extract would have been easier to see on the screenshots. This is true. The problem was the residual mask that caused two comparatively large areas to not be defined as basins by r.watershed. That's shen I removed that map and started over with the full-size DEM rather than the one 'clipped' to the vector basin boundaries. Now I get too many small basins but the former white areas with null elevations do contain identified basins. Try to set the region and MASK before the analysis, then don't modify these settings during the analysis. Something like g.region vect=basins align=dem_proj g.region res=10m -a r.resamp.stats in=dem_proj out=dem_10m method=average -w v.to.rast in=basins out=MASK type=area use=val val=1 r.watershed elevation=dem_10m acc=dem_10m.acc basin=dem_10m.basin threshold=15 r.mapcalc dem_10m.acc.w = dem_10m.acc * weight r.stream.extract elevation=dem_10m acc=dem_10m.acc.w stream_rast=dem_10m.streams stream_vect=dem_10m_streams threshold=??? This is different. I'll work on this today. The r.stream.extract, r.stream.basins, r.stream.order, and r.basin modules are essential for the two current big projects. So, I want to learn and better understand how to use them to get meaningful results. You may need to try different values for threshold with r.stream.extract in order to get the desired detail. I've tried different thresholds for r.watershed but not -- yet -- for r.stream.extract. I need to try the latter as well as looking at vector output. HTH, I'm sure it will. Thank you very much, Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.stream.extract: map mis-match error
On Fri, 20 Apr 2012, Markus Metz wrote: g.region res=10m -a r.resamp.stats in=dem_proj out=dem_10m method=average -w What is the reason to run r.resamp.stats if the region's resolution has been changed to that cell size? Thanks, Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.stream.extract: map mis-match error
On Fri, 20 Apr 2012, Markus Metz wrote: The resolution has been decreased, in this case several of the original cells fall into one new cell. A reasonably accurate new value can be obtained by using the average of all cells falling into a new cell. If on the contrary resolution is changed from e.g. 30 to 10 feet (increased), r.resamp.interp with bilinear or bicubic resampling would be a good choice. Markus. Thank you for clarifying. I wasn't thinking about what happens to cells when the resolution is made more coarse so I did not see the necessity of running r.resamp.stats. Now I do. Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] r.stream.extract: map mis-match error
On Fri, 20 Apr 2012, Markus Metz wrote: Try to set the region and MASK before the analysis, then don't modify these settings during the analysis. Something like g.region vect=basins align=dem_proj g.region res=10m -a r.resamp.stats in=dem_proj out=dem_10m method=average -w v.to.rast in=basins out=MASK type=area use=val val=1 r.watershed elevation=dem_10m acc=dem_10m.acc basin=dem_10m.basin threshold=15 r.mapcalc dem_10m.acc.w = dem_10m.acc * weight r.stream.extract elevation=dem_10m acc=dem_10m.acc.w stream_rast=dem_10m.streams stream_vect=dem_10m_streams threshold=??? My only modifications to the above were to run r.param.scale after r.watershed and r.mapcalc to calculate weight from the r.param.scale tangential curve output maps before calling r.mapcalc to apply the weights. Could these be problematic? The results are still GRASS 6.5.svn :~/grassdata r.stream.extract elev=dem_10m acc=dem_10m.acc.w stream_rast=dem_10m.rstreams.w stream_vect=dem_10m.vstreams.w thresh=1000 --o Load input maps and get start points... ERROR: Accumulation map does not match elevation map! I'm completely puzzled ... and a bit frustrated that the same error is thrown so consistently. Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] DTM with contour lines and points
Thank you Paolo! Best regards! Pedro - Original Message - From: Paolo Cavallini Il 20/04/2012 00:51, Pedro Venâncio ha scritto: I thought a way to get around, which is to convert the contours to equally spaced points and join these points whith the elevation points layer. Is there a more correct and straightforward way to do? your real data are vertices anyway, so I think extracting them and patching them with points is the straightforward way. All the best. -- Paolo Cavallini See: http://www.faunalia.it/pc ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] v.triangle -- module to produce TIN with breaklines using Triangle utility
Hi all. I wrote a shell-script module v.triangle that is front-end for the famous Triangle utility (http://www.cs.cmu.edu/~quake/triangle.html) of J.R. Shewchuk. I'm planning to add it to GRASS-Addons wiki page :) Triangle makes exact Delaunay triangulations, constrained Delaunay triangulations, conforming Delaunay triangulations and high-quality triangular meshes. On GIS terminology, it produces 2D TIN, optionally with breaklines. Link: https://raw.github.com/amuriy/GRASS-scripts/master/v.triangle P.S. It generally works but centroids in final TIN have 0 heights. Now I think about some hack to make the right centroids in all areas of TIN. - Comparison of the one resulting TIN with the TIN produced in ArcView 3D Analyst see in linked PDF ( http://dl.dropbox.com/u/42016908/ArcView_GRASS_TIN_breaklines.pdf) - ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.triangle -- module to produce TIN with breaklines using Triangle utility
Hi, I'm not sure to understand the difference between your v.triangle and the v.delaunay ( http://grass.osgeo.org/grass64/manuals/html64_user/v.delaunay.html) already in grass core ... for what I see in your pdf exemple, it seems that your new module is giving almost the same result as v.delaunay would do ... can you explain the differences ? I like to learn new things in grass ;) cheers, Sylvain 2012/4/20 Alexander Muriy amu...@gmail.com Hi all. I wrote a shell-script module v.triangle that is front-end for the famous Triangle utility (http://www.cs.cmu.edu/~quake/triangle.html) of J.R. Shewchuk. I'm planning to add it to GRASS-Addons wiki page :) Triangle makes exact Delaunay triangulations, constrained Delaunay triangulations, conforming Delaunay triangulations and high-quality triangular meshes. On GIS terminology, it produces 2D TIN, optionally with breaklines. Link: https://raw.github.com/amuriy/GRASS-scripts/master/v.triangle P.S. It generally works but centroids in final TIN have 0 heights. Now I think about some hack to make the right centroids in all areas of TIN. - Comparison of the one resulting TIN with the TIN produced in ArcView 3D Analyst see in linked PDF ( http://dl.dropbox.com/u/42016908/ArcView_GRASS_TIN_breaklines.pdf) - ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
