Hello, that makes sense. Might I suggest to take a look at JTS Topology Suite Technical Specifications fig. 6 that seems to display most common issues that could be eliminated with GRASS cleaning tools too.
Maris. 2011/12/2 Markus Metz <[email protected]>: > On Fri, Dec 2, 2011 at 12:43 PM, Maris Nartiss <[email protected]> wrote: >> Pardon my ignorance, >> how is possible to distinguish areas without centroids from holes? >> And why it doesn't make sense? > > A hole is a nothing in a something. If there is no something all > around the hole there is no hole. IOW, an area without a centroid is a > hole if it is completely surrounded by other areas with centroids, > otherwise that area is not a hole because it shares one or more > boundaries with the outer void. This does not make sense logically > because then there are two indistinguishable voids bordering each > other. These two voids can just as well be combined into one, lest > there is something special about one of the two voids, but that you > could only tell if there is a centroid in one void, rendering it > non-void. > > Markus M >> >> Maris, >> just finished converting and cleaning CAD (spaghetti) lines + points >> to valid areas. >> >> 2011/12/2 Markus Metz <[email protected]>: >>> >>> * for areas without centroids that are not holes. Areas without >>> centroids that are not holes are topologically correct but do not make >>> sense logically. _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
