[GRASS-user] Merge parallel roads
Hi, I need to merge parallel roads, like highway lanes, into one. I've looked around a bit and found solutions for ArcGIS (Collapse Dual Lines To Centerline) and for OSM XML files (Skeletron), but nothing that works straight in GRASS. What's the best way of doing this in GRASS? Cheers, Hendrik -- If your dreams don't scare you, then you are not dreaming big enough. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Merge parallel roads
On Sun, Jun 9, 2013 at 10:11 AM, Hendrik Hoeth ho...@linta.de wrote: Hi, I need to merge parallel roads, like highway lanes, into one. I've looked around a bit and found solutions for ArcGIS (Collapse Dual Lines To Centerline) and for OSM XML files (Skeletron), but nothing that works straight in GRASS. What's the best way of doing this in GRASS? I have an unsubmitted module v.centerline which extracts the centerline from irregular vector polygon(s). Perhaps this approach could be used here as well. It works like this (I would be pleased to make this script available to a user who wants to make it production ready as I don't find the time): - extract vertices from polygon - triangulate (v.voronoi) - restrict to polygon of interest (v.overlay, maybe not needed for you) - TODO: here add remove-boundaries magic (with convex hull?) - skeletonize (v.net.spanningtree) - TODO: extract longest line (no idea) I think that GRASS 7 should get a generic v.centerline which does the job for both lines as well as polygons. Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Merge parallel roads
Markus N wrote: I have an unsubmitted module v.centerline which extracts the centerline from irregular vector polygon(s). Perhaps this approach could be used here as well. It works like this (I would be pleased to make this script available to a user who wants to make it production ready as I don't find the time): is the prototype working well? or is it still at the theoretical/ experimental stage? I have thought about this problem a lot, it is related to the classic river mile problem which requires defining the center line of the river in a non-arbitrary way. the basic idea is to combine both parallel lines into a single map, run v.buffer to enclose them both, then get a big mosquito to pull all the volume out of the buffer until it is thinned to a single line. for two parallel lines it is not so bad, but when you get splits and convergences and islands it gets ugly. actually the raster tools are pretty good for it but they don't work well when the length:width ratio are so very different as they are for a road or a river. maintaining a similar digitization scale/vertex resolution as the original polygon is another tricky but not critically important final detail. - skeletonize (v.net.spanningtree) - TODO: extract longest line (no idea) this is an approach I have not considered. will take a little thinking about. but if v.net.spanningtree solves the worst part of the problem then I think the longest line should not be so hard to solve with one of the v.net tools. there is a bit in the archives, as well as a user donated v.centerline module, http://thread.gmane.org/gmane.comp.gis.grass.devel/36271/focus=36290 http://thread.gmane.org/gmane.comp.gis.grass.devel/36294 More on the difficulties of the river mile problem and ideas about it: http://thread.gmane.org/gmane.comp.gis.grass.user/22063/focus=22097 see also: http://article.gmane.org/gmane.comp.gis.grass.devel/11504 http://thread.gmane.org/gmane.comp.gis.grass.user/24385 http://thread.gmane.org/gmane.comp.gis.grass.user/42693/focus=42722 http://search.gmane.org/?query=river+milegroup=gmane.comp.gis.grass.user regards, Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] problem add-ons and python (windows7)
Mattia wrote: I'm trying to solve my problem for a long time. I hope someone can help me. I'm not expert but I really want to istall 2 add-on on grass 6.4.3RC3 on my win7. The add-ons are r.basin and r.ipso. I think there are problem with the python.exe and the PATHS. When I launch from console r.ipso I receive this error: C:\Program Files (x86)\GRASS GIS 6.4.3RC3\extrabin\python.exe: can't open file 'r.ipso.py': [Errno 2] No such file or directory the trouble with those two scripts are that they are written in python, and GRASS 6 does not handle python addon scripts as well as it does compiled C modules and UNIX shell scripts. the bad news is as you experience they don't work out of the box right now on Windows. The good news is that it is fixable. By moving and renaming some of the files I could get them to run locally on Windows XP. -- it's a solvable problem. I just ran r.basin. gory technical details: the basic one is Python.Make in GRASS 6's include/Make dir is not currently set up to create the .bat file wrappers needed to launch the scripts there. And/or the set PATHENV in \etc\Init.bat is not working properly. (it knows about .py but doesn't know to associate it with GRASS's python.exe) Secondly, there is a .bat wrapper called %ADDONS%/scripts/r.basin.py.bat which should be in %ADDONS%, and be named r.basin.bat. It contains a single line, but that is wrong too, it should be set up for a python script but it is created for a UNIX shell script. It should read like: @%GRASS_PYTHON% %GRASS_ADDON_PATH%/r.basin %* then the %ADDONS%\r.basin.py renamed to just r.basin, and finally the batch file run as r.basin.bat. Then it works. The better solution is to fix the .py association with python.exe, but care is needed to pick the right one, and not hijack that setting for the entire computer, since other software might be using another version of python. I note that there are 2 python.exe. One in C:\Program Files (x86)\GRASS GIS 6.4.3RC3\extrabin\ and one in C:\Program Files (x86)\GRASS GIS 6.4.3 RC3\Pyton27\. I think that last one is the right and I think that probably there is an error with the PATH. It is possible? do you really have a python.exe in your ...\GRASS GIS 6.4.3 RC3\Python27\ directory? For me it is only in ...\extrabin\ and in Python27\ there is only support files. As of last night's nightly build, 6.4.3svn explicitly expects to find its python.exe in the \extrabin\ dir. Can anyone drive me to the solution? I would need to know where setting the different path beacuse I'm noob! I also see that there is a folder in C: User\AppData\Roaming\GRASS6\addons... It is normal that the add-ons are istalled ther instead of in GRASS GIS 6.4.3RC3 directory? Yes, because the User can always write to their own AddData directly, but on a multi-user or managed (corporate) system the user may not have permission to change or add files to C:\Program Files. There is a %GRASS_ADDON_PATH% variable set which says where your personal scripts are stored. (can be set to multiple paths) When I launch r.basin I have an error that say aren't import sys, os and matplotlib. Even though I have istall matplotlib for Python27. I don't get that error, just the one from g.parser that it can't get the interface description (since it can't find the script). I'm surprised that sys and os can't be found, that indicates that your %PYTHONPATH% is broken since those two should always be built in. As for matplotlib I'm not sure if GRASS ships that, it might not so need to be installed manually. (however you do that on Windows) again, python + grass6 + MS Windows is a work in progress :) fortunately only a few of the addons for grass6 are written in python, so it's not a very widespread problem, but is certainly a pretty basic need and something we want to support for the future. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] problem add-ons and python (windows7)
another potential problem I see is that the Makefile for both modules are calling Script.make instead of Python.make. luckily, none of the problems are fatal, will get fixed, and can be fixed in our backend server, i.e. no user-software upgrade will be needed. the biggest question mark for me is the one of associating .py with the correct python installation in a good-neighbor way. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Structure of sig file
Hi, inspired by Moritz's comments, I have added an example to the manual page of i.gensig, see new NOTES section: http://grass.osgeo.org/grass64/manuals/i.gensig.html (likewise for GRASS 6.5 and 7) Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] R: Re: problem add-ons and python (windows7)
And/or the set PATHENV in \etc\Init.bat is not working properly. (it knows about .py but doesn't know to associate it with GRASS's python.exe) Honestly I have not found the PATHENV in \etc\Init.bat. Is it a problem? I tryed to know which one is the path that corresponds to python.exe but I wasn't able. The command try to open .py file always with pythom.exe from \extrabin. Secondly, there is a .bat wrapper called %ADDONS%/scripts/r.basin.py.bat which should be in %ADDONS%, and be named r.basin.bat. I wasn't able to find where to set %ADDONS% too. I saw only % GRASS_ADDON_PATH%. So confused :) Mattia Messaggio originale Da: hamis...@yahoo.com Data: 09/06/2013 13.33 A: grass-user@lists.osgeo.org, Mattia Riccadonnamatti...@libero.it Ogg: Re: [GRASS-user] problem add-ons and python (windows7) Mattia wrote: I'm trying to solve my problem for a long time. I hope someone can help me. I'm not expert but I really want to istall 2 add-on on grass 6.4.3RC3 on my win7. The add-ons are r.basin and r.ipso. I think there are problem with the python.exe and the PATHS. When I launch from console r.ipso I receive this error: C:\Program Files (x86)\GRASS GIS 6.4.3RC3\extrabin\python.exe: can't open file 'r.ipso.py': [Errno 2] No such file or directory the trouble with those two scripts are that they are written in python, and GRASS 6 does not handle python addon scripts as well as it does compiled C modules and UNIX shell scripts. the bad news is as you experience they don't work out of the box right now on Windows. The good news is that it is fixable. By moving and renaming some of the files I could get them to run locally on Windows XP. -- it's a solvable problem. I just ran r.basin. gory technical details: the basic one is Python.Make in GRASS 6's include/Make dir is not currently set up to create the .bat file wrappers needed to launch the scripts there. And/or the set PATHENV in \etc\Init.bat is not working properly. (it knows about .py but doesn't know to associate it with GRASS's python.exe) Secondly, there is a .bat wrapper called %ADDONS%/scripts/r.basin.py.bat which should be in %ADDONS%, and be named r.basin.bat. It contains a single line, but that is wrong too, it should be set up for a python script but it is created for a UNIX shell script. It should read like: @%GRASS_PYTHON% %GRASS_ADDON_PATH%/r.basin %* then the %ADDONS%\r.basin.py renamed to just r.basin, and finally the batch file run as r.basin.bat. Then it works. The better solution is to fix the .py association with python.exe, but care is needed to pick the right one, and not hijack that setting for the entire computer, since other software might be using another version of python. I note that there are 2 python.exe. One in C:\Program Files (x86)\GRASS GIS 6.4.3RC3\extrabin\ and one in C:\Program Files (x86)\GRASS GIS 6.4.3 RC3\Pyton27\. I think that last one is the right and I think that probably there is an error with the PATH. It is possible? do you really have a python.exe in your ...\GRASS GIS 6.4.3 RC3\Python27\ directory? For me it is only in ...\extrabin\ and in Python27\ there is only support files. As of last night's nightly build, 6.4.3svn explicitly expects to find its python.exe in the \extrabin\ dir. Can anyone drive me to the solution? I would need to know where setting the different path beacuse I'm noob! I also see that there is a folder in C: User\AppData\Roaming\GRASS6\addons... It is normal that the add-ons are istalled ther instead of in GRASS GIS 6.4.3RC3 directory? Yes, because the User can always write to their own AddData directly, but on a multi-user or managed (corporate) system the user may not have permission to change or add files to C:\Program Files. There is a %GRASS_ADDON_PATH% variable set which says where your personal scripts are stored. (can be set to multiple paths) When I launch r.basin I have an error that say aren't import sys, os and matplotlib. Even though I have istall matplotlib for Python27. I don't get that error, just the one from g.parser that it can't get the interface description (since it can't find the script). I'm surprised that sys and os can't be found, that indicates that your %PYTHONPATH% is broken since those two should always be built in. As for matplotlib I'm not sure if GRASS ships that, it might not so need to be installed manually. (however you do that on Windows) again, python + grass6 + MS Windows is a work in progress :) fortunately only a few of the addons for grass6 are written in python, so it's not a very widespread problem, but is certainly a pretty basic need and something we want to support for the future. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] FreeBSD Compilation Error : Update config.guess and config.sub
On Tue, Dec 4, 2012 at 12:33 AM, Markus Neteler nete...@osgeo.org wrote: On Mon, Dec 3, 2012 at 6:48 PM, Pierre Stévens pie...@geobsd.com wrote: I found the latest version of those files here : http://git.savannah.gnu.org/cgit/config.git/tree/ Are they the good ones ? Perfect - I have updated the files in GRASS 7.svn. Please try again, I hope it now works for you. FYI: I have updated config.guess, config.sub, configure in all branches/trunk to the latest version to keep up with the autoconf improvements. Source: http://git.savannah.gnu.org/cgit/config.git/plain/ Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] R: Re: problem add-ons and python (windows7)
In addition, I used g.extension to get add-ons. And with that command there aren't make files in any folder. Have I to re-download them manually? In case, where have I to put make files? Messaggio originale Da: hamis...@yahoo.com Data: 09/06/2013 13.37 A: grass-user@lists.osgeo.org, Mattia Riccadonnamatti...@libero.it Ogg: Re: [GRASS-user] problem add-ons and python (windows7) another potential problem I see is that the Makefile for both modules are calling Script.make instead of Python.make. luckily, none of the problems are fatal, will get fixed, and can be fixed in our backend server, i.e. no user-software upgrade will be needed. the biggest question mark for me is the one of associating .py with the correct python installation in a good-neighbor way. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
