Note that there is also "v.generalize" (if you have the GRASS provider
activated in Processing). It implements many additional algorithms and
provides a comprehensive Help page.
It would be interesting to know which algorithm (and parameters) gave
you the best results!
Best,
Ben
On 27/06/2022 16:58, Johannes Kröger (WhereGroup) via Qgis-user wrote:
Hey Michael,
the algorithms involved are Douglas-Peucker and Visvalingam. With those
terms you might find some nice explanations and guidance online. Some
quick links:
- http://bl.ocks.org/msbarry/9152218
- https://dulldrums.github.io/polygon-reduction-algorithms-demo/
- https://ignf.github.io/CartAGen/docs/algorithms/line/visvalingam.html
For your use case (keeping the overall shape) I would try Visvalingam
first as that is pretty much its goal too.
Cheers, Hannes
Am 27.06.22 um 16:52 schrieb Michael.Dodd via Qgis-user:
I know there are various simplify tools in qgis but perhaps I don’t
understand how to use them best. I want to simplify i.e. reduce the
number of nodes in a polygon without changing the overall shape too
much for country or similar outlines. When I have tried this the
simplify tends to chop off bits that a human doing a manual
simplification would not, in some areas the simplification could loose
loads of nodes whereas in other areas it needs to keep more of them or
the overall shape will be greatly changed. Is there anyway round this
or am I asking for something that is not logical?
_______________________________________________
Qgis-user mailing list
[email protected]
List info:https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe:https://lists.osgeo.org/mailman/listinfo/qgis-user
--
Johannes Kröger / GIS-Entwickler/-Berater
---------------------------------------------
Schon gewusst?
In unserem Blog geben wir Tipps & Tricks zu Open-Source-GIS-Software
und berichten aus unserem Experten-Alltag:
https://wheregroup.com/blog/
---------------------------------------------
WhereGroup GmbH
Grevenweg 89
20537 Hamburg
Germany
Tel: +49 (0)228 / 90 90 38 - 36
Fax: +49 (0)228 / 90 90 38 - 11
[email protected]
www.wheregroup.com
Geschäftsführer:
Olaf Knopp, Peter Stamm
Amtsgericht Bonn, HRB 9885
-------------------------------
_______________________________________________
Qgis-user mailing list
[email protected]
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
_______________________________________________
Qgis-user mailing list
[email protected]
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
