Re: [GRASS-user] v.to.rast gives empty raster layer
Hi Moritz, I'm not sure what you mean by 'Maris' first part of the solution'. I saw only one part to Maris's suggestion (refining the region's resolution) because I said in my initial mail that I had set extents of the region to the contours_20m vector layer. Initially I did have a resolution of 20m and got an empty raster layer as a result. I share Micha's confusion about this. Although it doesn't make much sense to have a 20m cell size (my bad) I would have thought that v.to.rast would still have given me an output. Regards Hanlie 2011/5/3, Moritz Lennert mlenn...@club.worldonline.be: On 03/05/11 15:47, Micha Silver wrote: On 05/03/2011 04:34 PM, Moritz Lennert wrote: On 03/05/11 10:20, Micha Silver wrote: On 05/03/2011 09:11 AM, Hanlie Pretorius wrote: Hi Maris, Thanks, your suggestion worked. With the region's resolution set to 5m, I got some output. Hi Maris: Sorry for butting in on this, but I don't understand why the region resolution should make any difference to v.to.rast?? Would you mind to explain? From the v.to.rast manual: v.to.rast will only affect data in areas lying inside the boundaries of the current geographic region. Before running v.to.rast, the user should therefore ensure that the current geographic region is correctly set and that the region resolution is at the desired level. Thanks, Moritz What I'm trying to understand is the question about resolution. Would you expect, as Hanlie indicted, to get *no output* in the raster because of too course resolution? He claims that at 20m x 20m v.to.rast of a line feature created all NULL cells, but at 5m x 5m the lines did appear in the raster. ?? Hanlie didn't tell us whether he applied Maris' first part of the solution as well (but I guess he did): g.region vect=contours_20m I agree with you that resolution does not make the difference. However, I guess that Maris meant that having a 20m resolution seems too coarse for 20m contour lines, but even that is not clear as all depends on the topography of the region in question. If you have 100m altitude change for 50m horizontal change, then 20m is a bad choice of resolution, but if you have 100m altitude change for 1km horizontal change, it should be more than enough. So, in conclusion, the region's resolution setting can make a huge difference in v.to.rast, but in this particular case does not explain why there was no output. This is certainly linked to the region's extension. Moritz ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.to.rast gives empty raster layer
On 04/05/11 08:42, Hanlie Pretorius wrote: Hi Moritz, I'm not sure what you mean by 'Maris' first part of the solution'. I saw only one part to Maris's suggestion (refining the region's resolution) because I said in my initial mail that I had set extents of the region to the contours_20m vector layer. Initially I did have a resolution of 20m and got an empty raster layer as a result. I share Micha's confusion about this. Although it doesn't make much sense to have a 20m cell size (my bad) I would have thought that v.to.rast would still have given me an output. Rereading the original mail I see this: 2011/5/2, Hanlie Pretoriushanlie.pretor...@gmail.com: r.info for the result is: | Layer: contours_20m@CDNGI_DEM Date: Mon May 02 14:18:00 2011 | Mapset: CDNGI_DEM Login of Creator: hanlie | Location: SA_Lo_29E | DataBase: F:\grassdata | Title: Labels ( contours_20m@CDNGI_DEM ) | Timestamp: none | | | Type of Map: raster Number of Categories: 0 [snip] | Rows: 1772 | Columns: 1750 | Total Cells: 3101000 | Projection: Transverse Mercator | N: -3121229.69982072 S: -3156672.30728643 Res: 20.00147148 | E: -32474.90929218 W: -67483.27873573 Res: 20.00478254 | Range of data: min = 1620 max = 2460 [snip] As you can see from the number of categories (0), there is no information in this raster file. There are no category values, but there are data values, so your map actually is not empty. What does r.stats contours_20m@CDNGI_DEM give you ? 1) v.to.rast does create category labels by default. If you use the 'labelcol' parameter, then you get category values. Example in the NC demo dataset: v.to.rast elev_ned10m_cont10m out=contours col=level r.info contours: Number of Categories: 0 Range of data:min = 60.00 max = 150.00 2) v.to.rast elev_ned10m_cont10m out=contours col=level labelcol=cat r.info contours: Number of Categories: 150 Range of data:min = 60.00 max = 150.00 Moritz ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.to.rast gives empty raster layer
Oh, I see, thanks. r.stats input=contours_20m@CDNGI_DEM 1620-1623.294118 1639.764706-1643.058824 1659.529412-1662.823529 1679.294118-1682.588235 1699.058824-1702.352941 1718.823529-1722.117647 1738.588235-1741.882353 1758.352941-1761.647059 1778.117647-1781.411765 1797.882353-1801.176471 1817.647059-1820.941176 1837.411765-1840.705882 1857.176471-1860.470588 1876.941176-1880.235294 1900-1903.294118 1919.764706-1923.058824 1939.529412-1942.823529 1959.294118-1962.588235 1979.058824-1982.352941 1998.823529-2002.117647 2018.588235-2021.882353 2038.352941-2041.647059 2058.117647-2061.411765 2077.882353-2081.176471 2097.647059-2100.941176 2117.411765-2120.705882 2137.176471-2140.470588 2156.941176-2160.235294 2180-2183.294118 2199.764706-2203.058824 2219.529412-.823529 2239.294118-2242.588235 2259.058824-2262.352941 2278.823529-2282.117647 2298.588235-2301.882353 2318.352941-2321.647059 2338.117647-2341.411765 2357.882353-2361.176471 2377.647059-2380.941176 2397.411765-2400.705882 2417.176471-2420.470588 2436.941176-2440.235294 2456.705882-2460 * (Wed May 04 10:35:47 2011) Command finished (0 sec) For some reason I couldn't get the raster contours to display yesterday - another reason why I though the layer was empty. I adjusted the colour table an re-rendered the map with no effect. Today, however, it works and I can see it. Sorry about the confusion. 2011/5/4, Moritz Lennert mlenn...@club.worldonline.be: On 04/05/11 08:42, Hanlie Pretorius wrote: Hi Moritz, I'm not sure what you mean by 'Maris' first part of the solution'. I saw only one part to Maris's suggestion (refining the region's resolution) because I said in my initial mail that I had set extents of the region to the contours_20m vector layer. Initially I did have a resolution of 20m and got an empty raster layer as a result. I share Micha's confusion about this. Although it doesn't make much sense to have a 20m cell size (my bad) I would have thought that v.to.rast would still have given me an output. Rereading the original mail I see this: 2011/5/2, Hanlie Pretoriushanlie.pretor...@gmail.com: r.info for the result is: | Layer: contours_20m@CDNGI_DEM Date: Mon May 02 14:18:00 2011 | Mapset: CDNGI_DEM Login of Creator: hanlie | Location: SA_Lo_29E | DataBase: F:\grassdata | Title: Labels ( contours_20m@CDNGI_DEM ) | Timestamp: none | | | Type of Map: raster Number of Categories: 0 [snip] | Rows: 1772 | Columns: 1750 | Total Cells: 3101000 | Projection: Transverse Mercator | N: -3121229.69982072 S: -3156672.30728643 Res: 20.00147148 | E: -32474.90929218 W: -67483.27873573 Res: 20.00478254 | Range of data: min = 1620 max = 2460 [snip] As you can see from the number of categories (0), there is no information in this raster file. There are no category values, but there are data values, so your map actually is not empty. What does r.stats contours_20m@CDNGI_DEM give you ? 1) v.to.rast does create category labels by default. If you use the 'labelcol' parameter, then you get category values. Example in the NC demo dataset: v.to.rast elev_ned10m_cont10m out=contours col=level r.info contours: Number of Categories: 0 Range of data:min = 60.00 max = 150.00 2) v.to.rast elev_ned10m_cont10m out=contours col=level labelcol=cat r.info contours: Number of Categories: 150 Range of data:min = 60.00 max = 150.00 Moritz ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] DEM resolution from r.surf.contour
Hi, I'd like to ask a question related to another question I was asking recently about converting contour vectors to rasters and creating a DEM from the raster contours using r.surf.contour. My supplied vector contour layer has 20m intervals between contour lines. When I convert this to raster, the smallest region resolution I can use is 5m, otherwise v.to.rast runs out of memory. When I use r.surf.contour to create the DEM from the raster, which region resolution makes sense then? I set it to 20m because of the contour interval, but I'm starting to think that's not the best option because the interpolation between two contour lines should be as fine as possible. Any thoughts? Thanks Hanlie ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] OCR
Hello, This might seem a Little off topic, but maybe someone here can help me. I need to extract toponomical data from old digitized paper maps. I wish to explore *Optical character recognition (OCR). Does anyone has a suggestion/experience with this kind of challenge? Thank you, André Mano * -- --- Associação Leonel Trindade SOCIEDADE DE HISTÓRIA NATURAL Apartado 25 2564-909 Torres Vedras Portugal Sede e Biblioteca: rua Cavaleiros da Espora Dourada, 27A 2560 Torres Vedras Laboratório de Paleontologia e Paleoecologia: Polígono Industrial do Alto do Ameal 2565-641 Ramalhal http://alt-shn.blogspot.com www.alt-shn.org ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] g.extension lipo problem
Hi, I am running os x snow leopard (10.6.7). I have tried to install an extension in GRASS 6.4.1 (2011), but it throws a compilation error. I have searched the lists, with no luck, could anyone help me with this problem. Thanks Jason g.extension extension=i.landsat.toar Fetching i.landsat.toar from GRASS-Addons SVN (be patient)... Ai.landsat.toar/landsat_set.c Ai.landsat.toar/local_proto.h Ai.landsat.toar/main.c Ai.landsat.toar/description.html Ai.landsat.toar/landsat.c Ai.landsat.toar/earth_sun.c Ai.landsat.toar/landsat.h Ai.landsat.toar/landsat_met.c Ai.landsat.toar/Makefile Ai.landsat.toar/earth_sun.h U i.landsat.toar Checked out revision 46186. Compiling i.landsat.toar... test -d OBJ.i386-apple-darwin10.7.0 || mkdir -p OBJ.i386-apple-darwin10.7.0 gcc -I/Users/Shared/src/GRASS/grass-6.4.1-snow/dist.i386-apple-darwin10.7.0/include -Os -fexceptions -arch i386 -arch x86_64 -DPACKAGE=\grassmods\ -I/Users/Shared/src/GRASS/grass-6.4.1-snow/dist.i386-apple-darwin10.7.0/include -o OBJ.i386-apple-darwin10.7.0/earth_sun.o -c earth_sun.c gcc -I/Users/Shared/src/GRASS/grass-6.4.1-snow/dist.i386-apple-darwin10.7.0/include -Os -fexceptions -arch i386 -arch x86_64 -DPACKAGE=\grassmods\ -I/Users/Shared/src/GRASS/grass-6.4.1-snow/dist.i386-apple-darwin10.7.0/include -o OBJ.i386-apple-darwin10.7.0/landsat.o -c landsat.c landsat.c:4:23: error: grass/gis.h: No such file or directory landsat.c:4:23: error: grass/gis.h: No such file or directory lipo: can't figure out the architecture type of: /Users/jasonlessels/git/muttama/gis/muttama/muttama/.tmp/macintosh-3.localdomain/29713.0/ccdiXykN.out make: *** [OBJ.i386-apple-darwin10.7.0/landsat.o] Error 1 ERROR: Compilation failed, sorry. Please check above error messages.___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] g.extension lipo problem
Known issue - g.extension doesn't work on a Mac (or other systems?) without the original compiled source. I have a modbuild in /Library/GRASS/6.4, see the readme there for details. One aditional thing to do before using it is copy all the static *.a libraries from the GRASS application (/Applications/GRASS-6.4.app/Contents/MacOS/lib) to the modbuild/Modules/lib folder. Note that modbuild does not install the module, just compiles it, you must do that manually. You will also need to download the addon source manually. This should do it (do it in the modbuild/module) folder): svn co https://svn.osgeo.org/grass/grass-addons/[moduleclass]/[module] [module] where [moduleclass] is the named type of module (from the first dotted part of the module name, ie imagery for i, and [module] is the full module name, ie i.landsat.toar. On May 4, 2011, at 1:11 PM, Jason Lessels wrote: Hi, I am running os x snow leopard (10.6.7). I have tried to install an extension in GRASS 6.4.1 (2011), but it throws a compilation error. I have searched the lists, with no luck, could anyone help me with this problem. Thanks Jason g.extension extension=i.landsat.toar Fetching i.landsat.toar from GRASS-Addons SVN (be patient)... Ai.landsat.toar/landsat_set.c Ai.landsat.toar/local_proto.h Ai.landsat.toar/main.c Ai.landsat.toar/description.html Ai.landsat.toar/landsat.c Ai.landsat.toar/earth_sun.c Ai.landsat.toar/landsat.h Ai.landsat.toar/landsat_met.c Ai.landsat.toar/Makefile Ai.landsat.toar/earth_sun.h U i.landsat.toar Checked out revision 46186. Compiling i.landsat.toar... test -d OBJ.i386-apple-darwin10.7.0 || mkdir -p OBJ.i386-apple-darwin10.7.0 gcc -I/Users/Shared/src/GRASS/grass-6.4.1-snow/dist.i386-apple-darwin10.7.0/include -Os -fexceptions -arch i386 -arch x86_64 -DPACKAGE=\grassmods\ -I/Users/Shared/src/GRASS/grass-6.4.1-snow/dist.i386-apple-darwin10.7.0/include -o OBJ.i386-apple-darwin10.7.0/earth_sun.o -c earth_sun.c gcc -I/Users/Shared/src/GRASS/grass-6.4.1-snow/dist.i386-apple-darwin10.7.0/include -Os -fexceptions -arch i386 -arch x86_64 -DPACKAGE=\grassmods\ -I/Users/Shared/src/GRASS/grass-6.4.1-snow/dist.i386-apple-darwin10.7.0/include -o OBJ.i386-apple-darwin10.7.0/landsat.o -c landsat.c landsat.c:4:23: error: grass/gis.h: No such file or directory landsat.c:4:23: error: grass/gis.h: No such file or directory lipo: can't figure out the architecture type of: /Users/jasonlessels/git/muttama/gis/muttama/muttama/.tmp/macintosh-3.localdomain/29713.0/ccdiXykN.out make: *** [OBJ.i386-apple-darwin10.7.0/landsat.o] Error 1 ERROR: Compilation failed, sorry. Please check above error messages.___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user - William Kyngesburye kyngchaos*at*kyngchaos*dot*com http://www.kyngchaos.com/ Earth: Mostly harmless - revised entry in the HitchHiker's Guide to the Galaxy ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
