On Sat, Jan 17, 2015 at 10:12 PM, Thayer Young <[email protected]> wrote: > > I have two shapefiles that I imported into GRASS 6.4.5 using v.in.ogr. One > is a polygon file of building footprints. The second is a polyline of the > pavement edges of urban streets. I am trying to convert this into street > area. I used v.clean, v.type (to switch from line to boundaries), and > v.centroids. This conversion process gives me street areas but also creates > doughnut holes corresponding to the area inside of a city block outlined by > the streets. For the most part the doughnut holes contain buildings, so I am > trying to use v.select to select the areas that do not contain buildings. I > have not been able to get anything besides "overlap" to work. Overlap is not > good enough though because many of the buildings have shared nodes with the > streets, for example where a driveway runs along one side of a house. I > checked and my version of GRASS was compiled with the following GEOS details: > > --with-geos=/Library/Frameworks/GEOS.framework/Versions/3/unix/bin/geos-config > > Below is an example of an error that I am getting when I try anything besides > overlap: > > v.select --overwrite ainput=EdgePav_cent@PERMANENT binput=Bldg@PERMANENT > output=Pav_sel operator=contains > WARNING: Vector map <Pav_sel> already exists and will be overwritten > Building spatial index... > Processing features... > ERROR: IllegalArgumentException: point array must contain 0 or >1 elements
In the past few days Markus Metz has fixed some topology issues in GRASS GIS 7 (potentially to be backported while that's a big task). Do you have any chance to try this in GRASS 7, downloading a version newer than RC1 (fixes will go into RC2)? markusN _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
