Re: [GRASS-user] two questions: snap and close lines
Il 26/01/2012 20:41, Markus Metz ha scritto: On Mon, Jan 23, 2012 at 8:00 PM, Paolo Cavallini cavall...@faunalia.it wrote: Hi all. A couple of issues I ran into today: - I have a layer with some good and some bad polygons; how do I import it into GRASS letting the bad ones snapping onto the good ones, and not vice versa? You could try v.edit, otherwise it will be hand-editing with a digitizer. With topological vectors, snapping one set of polygons to another set of polygons does not make sense, because there are no polygons in topological vectors, only shared boundaries. That is probably the reason why this functionality is not available in grass. Hi Markus M, thanks for your reply. Let me explain better my use case: - I have a shapefile, with (almost) adjacent polygons - if I import them, I can snap the almost adjacent lines, and get common boundaries - the problem is that I cannot control which of the two adjacent lines stay fixed, and which one moves to it - I know that of the two polygons, one is good (certified), the other is not; so I want the first to remain fixed, and have the other snap to it. Did I explain myself better? For contour lines, you would need to patch the vector with contour lines with a vector created with v.in.region type=line, then break lines at intersections, convert lines to boundaries, add centroids. This assumes that not closed contour lines have endpoints exactly at the extents of the vector, e.g. if the western edge of the contour vector is 30 and there is an open contour line ending at say 29., this will not work. If the contour lines were produced with r.contour, this should work. In practice: #set the region around contour v.in.region output=region_line type=line v.patch input=contour,region_line output=patched v.clean input=patched@paolo type=line tool=snap thresh=1 output=patched_1 v.clean input=patched@paolo type=line tool=break output=patched_break v.type input=patched_break@paolo output=patched_break_boundaries type=line,boundary v.centroids input=patched_break_boundaries output=polygons It mostly works, but apparently breaking does not (only closed rings become different polygons). In the meantime, I spotted a few minor issues in the qgis-grass interface, I'm going to fix them. Thanks a lot. -- Paolo Cavallini - Faunalia www.faunalia.eu Full contact details at www.faunalia.eu/pc ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.generalize: strange behaviour on win?
Il 26/01/2012 20:53, Markus Metz ha scritto: You would need to provide the input, not the output as an example. https://int.faunalia.it/~paolo/province.zip Considering the detail of the output and the threshold used, it is no surprise that not all boundaries were generalized because that would break topology. If you want to generalize with a threshold of 10, I would recommend to first remove all areas with a size up to 10. This is not the point. The very same input and command work in Linux, leave ungeneralized boundaries in Windows. If you consider that also r.to.vect for lines also behaves differently between the two OSs, I suspect an OS-specific bug here. Any confirmation? Thanks a lot. -- Paolo Cavallini - Faunalia www.faunalia.eu Full contact details at www.faunalia.eu/pc ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] two questions: snap and close lines
On Fri, Jan 27, 2012 at 1:02 PM, Paolo Cavallini cavall...@faunalia.it wrote: Il 26/01/2012 20:41, Markus Metz ha scritto: On Mon, Jan 23, 2012 at 8:00 PM, Paolo Cavallini cavall...@faunalia.it wrote: Hi all. A couple of issues I ran into today: - I have a layer with some good and some bad polygons; how do I import it into GRASS letting the bad ones snapping onto the good ones, and not vice versa? You could try v.edit, otherwise it will be hand-editing with a digitizer. With topological vectors, snapping one set of polygons to another set of polygons does not make sense, because there are no polygons in topological vectors, only shared boundaries. That is probably the reason why this functionality is not available in grass. Hi Markus M, thanks for your reply. Let me explain better my use case: - I have a shapefile, with (almost) adjacent polygons - if I import them, I can snap the almost adjacent lines, and get common boundaries - the problem is that I cannot control which of the two adjacent lines stay fixed, and which one moves to it - I know that of the two polygons, one is good (certified), the other is not; so I want the first to remain fixed, and have the other snap to it. Did I explain myself better? The only two options I can think of is giving v.edit a try, otherwise hand-editing. For contour lines, you would need to patch the vector with contour lines with a vector created with v.in.region type=line, then break lines at intersections, convert lines to boundaries, add centroids. This assumes that not closed contour lines have endpoints exactly at the extents of the vector, e.g. if the western edge of the contour vector is 30 and there is an open contour line ending at say 29., this will not work. If the contour lines were produced with r.contour, this should work. In practice: #set the region around contour v.in.region output=region_line type=line v.patch input=contour,region_line output=patched v.clean input=patched@paolo type=line tool=snap thresh=1 output=patched_1 v.clean input=patched@paolo type=line tool=break output=patched_break v.type input=patched_break@paolo output=patched_break_boundaries type=line,boundary v.centroids input=patched_break_boundaries output=polygons It mostly works, but apparently breaking does not (only closed rings become different polygons). Why does breaking not work? Maybe you need remove duplicates and clean small angles at nodes. You could try v.clean input=patched@paolo type=line tool=snap,break,rmdupl,rmsa thresh=1,0,0,0 output=patched_1 or in grass 7 v.clean input=patched@paolo type=line tool=snap thresh=1 output=patched_1 -c Markus M ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.generalize: strange behaviour on win?
On Fri, Jan 27, 2012 at 1:32 PM, Paolo Cavallini cavall...@faunalia.it wrote: Il 26/01/2012 20:53, Markus Metz ha scritto: You would need to provide the input, not the output as an example. https://int.faunalia.it/~paolo/province.zip Considering the detail of the output and the threshold used, it is no surprise that not all boundaries were generalized because that would break topology. If you want to generalize with a threshold of 10, I would recommend to first remove all areas with a size up to 10. This is not the point. The very same input and command work in Linux, leave ungeneralized boundaries in Windows. I tried v.generalize on the Province_general3 shapefile on Linux with type=boundary method=douglas threshold=10 and it did not modify any boundaries. I also tried the input province shapefile and get the same output. That is, if Province_general3 has been generated on windows, I do get the same result on Linux, no difference between the OS's. Are you using an older grass version on Linux? Markus M ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.generalize: strange behaviour on win?
Il 27/01/2012 19:02, Markus Metz ha scritto: same output. That is, if Province_general3 has been generated on windows, I do get the same result on Linux, no difference between the OS's. Are you using an older grass version on Linux? aptitude show grass Versione: 6.4.1-1 Thanks. -- Paolo Cavallini - Faunalia www.faunalia.eu Full contact details at www.faunalia.eu/pc ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] two questions: snap and close lines
Il 27/01/2012 18:53, Markus Metz ha scritto: The only two options I can think of is giving v.edit a try, otherwise hand-editing. Urgh! Too bad, thanks anyway. Why does breaking not work? Maybe you need remove duplicates and clean small angles at nodes. You could try v.clean input=patched@paolo type=line tool=snap,break,rmdupl,rmsa thresh=1,0,0,0 output=patched_1 I'm not quite sure break do not work: new nodes are there, but in subsequent steps they are not treated as closed polygons. Thanks. -- Paolo Cavallini - Faunalia www.faunalia.eu Full contact details at www.faunalia.eu/pc ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.generalize: strange behaviour on win?
On Fri, Jan 27, 2012 at 7:01 PM, Paolo Cavallini cavall...@faunalia.it wrote: Il 27/01/2012 19:02, Markus Metz ha scritto: same output. That is, if Province_general3 has been generated on windows, I do get the same result on Linux, no difference between the OS's. Are you using an older grass version on Linux? aptitude show grass Versione: 6.4.1-1 v.generalize is broken in 6.4.1 Markus M ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] 6.5svn Crash Report
I just ran 'svn up': 14:00 PST Friday 2012-01-27, configured, built, and installed the latest code. Didn't record the build number. Within the wxPython GUI I opened a point map and tried to query a point for information about it. GRASS immediately crashed. The virtual console shows: GRASS 6.5.svn (Washington-SPCS):~/grassdata/Washington-SPCS/Buckhorn dbmi: Protocol error GRASS_INFO_ERROR(1491,1): Unable to open database /home/rshepard/grassdata/Washington-SPCS/Buckhorn/dbf/ GRASS_INFO_END(1491,1) GRASS_INFO_ERROR(1494,1): Unable to describe table Buckhorn_Surface_Water_Stations GRASS_INFO_END(1494,1) dbmi: Protocol error GRASS_INFO_ERROR(1516,1): Unable to open database /home/rshepard/grassdata/Washington-SPCS/Buckhorn/dbf/ GRASS_INFO_END(1516,1) GRASS_INFO_ERROR(1519,1): Unable to describe table Buckhorn_Surface_Water_Stations GRASS_INFO_END(1519,1) I had imported this map from a shapefile a few weeks ago but had not looked at it before now. Where do I start looking for the problem with opening the GRASS database? Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] 6.5svn Crash Report [UPDATE]
Just tried to re-import the file. Command window shows: (Fri Jan 27 14:44:02 2012) v.in.ogr dsn=/home/rshepard/projects/washington/buckhorn/spatial/Buckhorn_Surface_Water_Stations.shp layer=Buckhorn_Surface_Water_Stations output=Buckhorn_Surface_Water_Stations --overwrite -e -w Vector map Buckhorn_Surface_Water_Stations already exists and will be overwritten Projection of input dataset and current location appear to match Vector map Buckhorn_Surface_Water_Stations already exists and will be overwritten dbmi: Protocol error Unable to open database /home/rshepard/grassdata/Washington-SPCS/Buckhorn/dbf/ by driver dbf Unable open database /home/rshepard/grassdata/Washington-SPCS/Buckhorn/dbf/ by driver dbf Unable to find table Buckhorn_Surface_Water_Stations linked to vector map Buckhorn_Surface_Water_Stations ERROR: Unable to delete vector map Buckhorn_Surface_Water_Stations (Fri Jan 27 14:44:03 2012) Command finished (0 sec) Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] 6.5svn Crash Report
Rich wrote: I just ran 'svn up': 14:00 PST Friday 2012-01-27, configured, built, and installed the latest code. Didn't record the build number. Within the wxPython GUI I opened a point map and tried to query a point for information about it. GRASS immediately crashed. The virtual console shows: ... dbmi: Protocol error It didn't like a change to db__recv_procnum() in lib/db/dbmi_base/xdrprocedure.c made 2 hours ago. it's now back to the old (working) way in devbr6, cd lib/db/ svn up make trunk remains broken for now. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] 6.5svn Crash Report
On Fri, 27 Jan 2012, Hamish wrote: It didn't like a change to db__recv_procnum() in lib/db/dbmi_base/xdrprocedure.c made 2 hours ago. it's now back to the old (working) way in devbr6, cd lib/db/ svn up make Hamish, Did the above (including 'make install') and see no difference. Same error message when I try to query a point for the attributes: GRASS 6.5.svn (Washington-SPCS):~/grassdata/Washington-SPCS/Buckhorn dbmi: Protocol error GRASS_INFO_ERROR(5972,1): Unable to open database /home/rshepard/grassdata/Washington-SPCS/Buckhorn/dbf/ GRASS_INFO_END(5972,1) GRASS_INFO_ERROR(5974,1): Unable to describe table Buckhorn_Surface_Water_Stations GRASS_INFO_END(5974,1) dbmi: Protocol error GRASS_INFO_ERROR(5997,1): Unable to open database /home/rshepard/grassdata/Washington-SPCS/Buckhorn/dbf/ GRASS_INFO_END(5997,1) GRASS_INFO_ERROR(5999,1): Unable to describe table Buckhorn_Surface_Water_Stations GRASS_INFO_END(5999,1) Thanks, Rich ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
