Hi, QGIS already has access to tons of generalisation options via the grass v.generalise tool
http://grass.osgeo.org/grass64/manuals/v.generalize.html Split into four categeories - Generalisation, Smoothing, Displacement, Network Generalisation. Is there a reason those can't be used? I wonder how many implementations of Douglas Peucker QGIS already has? Re-implementing other ones when they already exist doesn't seem optimal. Of course maybe you want a new one, but then I'd suggest maybe it could be added to Grass and that in turn would automatically feed into QGIS. Cheers, Jonathan On 3 February 2014 14:29, kimaidou <[email protected]> wrote: > Hi, > > We definitely need a better simplify algo in QGIS than Douglas Peucker. It > is very fast, but does not really preserve the "shape" of polygons/lines > and does not preserve topology. Your work seems interesting. Is you > approach similar to Visvalingam algo (used for example in Mapshaper : > http://mapshaper.org/ ) ? Does it preserve topology ? > Having a simplifier that can preserver topology while being fast like > Visvalingam would be great indeed ! > > ps: sorry to bring personnal will in response of your topic instead of > really answering your question.. > > Michael > > > 2014-02-03 giulianc51 <[email protected]>: > > Hi all, >> >> >> I do not know if this is the right place to talk about it but I think I >> have found a small problem in the plugin fTools, particularly in the >> "Simplify geometry" of the module "Geometry tool"; >> >> more precisely, the problem is in the RDP algorithm used by the >> function; >> >> nothing dramatic, the procedure works properly and provides a >> simplified line, but I have isolated some cases in which the solution >> is not optimal: some points, not needed for the definition of the line, >> are left; >> >> to sum up, I put some considerations in some slides here >> http://www.slideshare.net/giulianc/clean-lines-presentation; >> >> can you tell me where and how it can be of interest to discuss this >> topic? >> >> thanks, best regards, sfm+Gtbe(*) :-) >> giuliano curti >> >> >> (*) sorry for my (+ Google translation) bad english :-) >> _______________________________________________ >> Qgis-developer mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/qgis-developer >> > > > _______________________________________________ > Qgis-developer mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-developer > -- This transmission is intended for the named addressee(s) only and may contain sensitive or protectively marked material up to RESTRICTED and should be handled accordingly. Unless you are the named addressee (or authorised to receive it for the addressee) you may not copy or use it, or disclose it to anyone else. If you have received this transmission in error please notify the sender immediately. All email traffic sent to or from us, including without limitation all GCSX traffic, may be subject to recording and/or monitoring in accordance with relevant legislation.
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