Markus Metz wrote: > Moritz Lennert wrote: >> On 30/11/11 18:37, Markus Metz wrote: >>> >>> Moritz Lennert wrote: >>>> >>>> On 30/11/11 14:38, Markus Metz wrote: >>>>> >>>>> >>>>> It seems to me that the confusion arises because you made use of >>>>> features that allow you to skip topological cleaning which is not the >>>>> default and not recommended. >>>> >>>> >>>> >>>> Maybe this calls for a v.check.topology module ? Or an option in v.build >>>> or >>>> v.clean which does that (i.e. just check, not clean) ? >>> >>> >>> Good idea. I would opt for a new option/flag for v.build, which can >>> already provide rather detailed diagnostics, e.g. dumping topology. >>> Something like v.build -e for extended topology checks? >> >> >> +1 >> >> Now the question is: which checks should be performed ? > > Existing checks report the number of incorrect boundaries, duplicate > centroids and centroids outside areas. These are quick and easy to > catch. > > I would suggest to add new checks > * for intersecting boundaries indicating duplicate boundaries and/or > overlapping areas > * for boundaries and lines of zero length (not sure how much harm > zero length boundaries do but it's safer to have them removed) > * for areas without centroids that are not holes. Areas without > centroids that are not holes are topologically correct but do not make > sense logically. > > There are probably special cases not captured with all these checks, > but additional checks could be added later on. >
Additional tests for corrupt topology are now in trunk r49553. Please try v.build -e. Markus M _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
