Markus, Thanks, that means this is no bug then.
However, in my specific case this behaviour is problematic (I do need to merge small areas into existing/real areas), so maybe a suggestion could be to control that behaviour through an option? Anyway, as I'm not able to code it myself in C, so this is just a wish! Thanks for the time you spent looking into my problem, this is much appreciated as usual, Pierre 2011/9/22 Markus Metz <markus.metz.gisw...@googlemail.com>: > On Thu, Sep 22, 2011 at 5:26 AM, Pierre Roudier > <pierre.roud...@gmail.com> wrote: >> BTW I confirm I got similar problems with the 6.4 series, >> > Thanks for the input vector, I could reproduce the effect. But I am > not sure if this is really a problem. The method to remove small areas > finds the neighbouring area with which the longest boundary is shared. > This neighbouring area can also be the surrounding "nothing" in which > case the area is not merged with a real area but erased. That is, my > first comment was wrong, areas are not always merged with a > neighbouring real area, only if this neighbouring real area is the one > with the longest shared boundary. The cleaning tool assumes that small > areas are spurious and removes them by merging or by erasing. In case > of ties, when there are two neighbours with equally longest shared > boundary, as in your case, whichever neighbour is checked first will > be used. That neighbour can also be the empty space around. > > Markus M > > >> >> 2011/9/22 Pierre Roudier <pierre.roud...@gmail.com>: >>> Thanks Markus, >>> >>> Here's an archive containing the input vector layer, along with >>> v.clean output: >>> https://df.bestgrid.org/quickshare/fb0bb3af778c8a03/vectors.tar.gz >>> >>> Here's the result of v.info -h on the output: >>> >>> COMMAND: r.to.vect input="c_means" output="foo" feature="area" >>> GISDBASE: /data/GRASSDATA >>> LOCATION: NZTM2000 MAPSET: BH USER: roudierp DATE: Thu Sep 15 17:29:53 2011 >>> --------------------------------------------------------------------------------- >>> COMMAND: v.clean input="foo" layer="1" >>> type="point,line,boundary,centroid,area,face,kernel" output="bar" >>> tool="rmar >>> ea" thresh=900 >>> GISDBASE: /data/GRASSDATA >>> LOCATION: NZTM2000 MAPSET: BH USER: roudierp DATE: Thu Sep 15 17:31:45 2011 >>> [Raster MASK present] >>> >>> Cheers, >>> >>> Pierre >>> >>> 2011/9/21 Markus Metz <markus.metz.gisw...@googlemail.com>: >>>> On Wed, Sep 21, 2011 at 12:51 AM, Pierre Roudier >>>> <pierre.roud...@gmail.com> wrote: >>>>> Markus, >>>>> >>>>> Sorry for this late reply as I was away from keyboard the last few days, >>>>> >>>>> I encountered this problem while testing the latest grass_svn (grass >>>>> 7). I can give it a shot using a stable version if you want, >>>> >>>> You can try, but I would be surprised if the result is any different. >>>> Can you make the vector available for testing, or can you reproduce >>>> this with a vector of the sample datasets? >>>> >>>> Markus M >>>>> >>>>> 2011/9/17 Markus Metz <markus.metz.gisw...@googlemail.com>: >>>>>> On Fri, Sep 16, 2011 at 6:28 AM, Pierre Roudier >>>>>> <pierre.roud...@gmail.com> wrote: >>>>>>> Dear list, >>>>>>> >>>>>>> I got a problem as I'm trying to remove small areas of a vector layer >>>>>>> using v.clean with the rmarea tool: some of these small areas that are >>>>>>> on the boundary of the layer are getting erased rather than being >>>>>>> merged with the closest polygon. >>>>>>> >>>>>>> Is that an expected behaviour? >>>>>> >>>>>> No, they should always be merged with a neighbouring area along the >>>>>> shared boundary. Areas are supposed to be erased only if they are >>>>>> isolated, i.e. do not share a boundary with another area. What GRASS >>>>>> version are you using? There was a bug which was fixed 2 years ago. >>>>>> >>>>>> Markus M >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> Scientist >>>>> Landcare Research, New Zealand >>>>> >>>> >>> >>> >>> >>> -- >>> Scientist >>> Landcare Research, New Zealand >>> >> >> >> >> -- >> Scientist >> Landcare Research, New Zealand >> > -- Scientist Landcare Research, New Zealand _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user