Nyall, I have this partially implemented and will get back with you in a few days.
On Wed, Oct 2, 2019 at 7:51 PM Nyall Dawson <nyall.daw...@gmail.com> wrote: > On Wed, 2 Oct 2019 at 01:30, C Hamilton <adenacult...@gmail.com> wrote: > > > > I am guessing this is working on Cartesian coordinates and not geodesic > which is fine if you have a local projection. I think I will go ahead and > implement some similar geodesic algorithms. Thank you for the GRASS link. > It will help. > > Hi Calvin, > > I think there's a strong use case for adding this to the c++ API. > Would you be willing to put together a proof of concept in Python code > and I'll port it to c++ for you? > > Nyall > > > > > > Thanks, > > > > Calvin > > > > On Tue, Oct 1, 2019 at 7:45 AM Áron Gergely <aron.gerg...@rasterra.nl> > wrote: > >> > >> Hi Calvin and list, > >> > >> Have you looked at the GRASS GIS v.generalize tool? > https://grass.osgeo.org/grass64/manuals/v.generalize.html > >> > >> The Douglas-Peucker algorithm is implemented there and I have used that > with (topologic)success recently on many touching polygons. Should work for > polylines too! > >> > >> Best regards, > >> Aron > >> > >> On 01/10/2019 08:19, Tim Sutton wrote: > >> > >> Hi > >> > >> On 26 Sep 2019, at 17:13, C Hamilton <adenacult...@gmail.com> wrote: > >> > >> Are there any geodesic QGIS algorithms that simplify lines? "Simplify" > just uses the projection units of measure. If there isn't I thought I would > add this to the Shape Tools plugin. I could easily implement the > Douglas-Peucker algorithm using geodesic math. > >> > >> For GPS tracks I also see a need to throw out all points that are less > than a certain distance or less than a certain time interval. I don't see > any simplification algorithms that make use of time. Am I just missing them? > >> > >> > >> No I don’t think we have any time based simplifiers - would be a great > addition! > >> > >> Regards > >> > >> Tim > >> > >> > >> > >> > >> Thanks, > >> > >> Calvin > >> _______________________________________________ > >> QGIS-Developer mailing list > >> QGIS-Developer@lists.osgeo.org > >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > >> > >> > >> — > >> > >> > >> > >> > >> > >> > >> > >> > >> Tim Sutton > >> > >> Co-founder: Kartoza > >> Ex Project chair: QGIS.org > >> > >> Visit http://kartoza.com to find out about open source: > >> > >> Desktop GIS programming services > >> Geospatial web development > >> GIS Training > >> Consulting Services > >> > >> Skype: timlinux > >> IRC: timlinux on #qgis at freenode.net > >> > >> I'd love to connect. Here's my calendar link to make finding time easy. > >> > >> > >> _______________________________________________ > >> QGIS-Developer mailing list > >> QGIS-Developer@lists.osgeo.org > >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > _______________________________________________ > > QGIS-Developer mailing list > > QGIS-Developer@lists.osgeo.org > > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer >
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