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<p>Hey Michael,</p>
<p>the algorithms involved are Douglas-Peucker and Visvalingam. With
those terms you might find some nice explanations and guidance
online. Some quick links:</p>
<p>- <a class="moz-txt-link-freetext" href="http://bl.ocks.org/msbarry/9152218">http://bl.ocks.org/msbarry/9152218</a><br>
- <a class="moz-txt-link-freetext" href="https://dulldrums.github.io/polygon-reduction-algorithms-demo/">https://dulldrums.github.io/polygon-reduction-algorithms-demo/</a><br>
-
<a class="moz-txt-link-freetext" href="https://ignf.github.io/CartAGen/docs/algorithms/line/visvalingam.html">https://ignf.github.io/CartAGen/docs/algorithms/line/visvalingam.html</a><br>
<br>
For your use case (keeping the overall shape) I would try
Visvalingam first as that is pretty much its goal too.</p>
<p>Cheers, Hannes<br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">Am 27.06.22 um 16:52 schrieb
Michael.Dodd via Qgis-user:<br>
</div>
<blockquote type="cite"
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<p class="MsoNormal"><span lang="EN-US">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?<o:p></o:p></span></p>
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