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Hi,<br>
I'm coming in late to this methodology discussion, so apologies if I
am off the mark.<br>
<br>
So by 'center line' I'm guessing you mean a line that is always
equidistant from the polygon boundary.<br>
<br>
I had a similar problem a few years back where I had to create road
center lines from a polygon road representation for a small country.<br>
<br>
After some experimentation on speed and efficacy, I came up with a
Python script that:<br>
<blockquote>merged (dissolved) all poygons) - but you only have 1
polygon :-)<br>
rasterised the polygon (as finely as you choose relevant to your
issue)<br>
ran r.thin<br>
vectorised the (now) single line of cells.<br>
ran a Douglas-Peuker style smoothing on the staircase lines<br>
</blockquote>
Worked like a dream for my purpose.<br>
Maybe you could adapt this logic flow to your needs?<br>
<br>
HTH,<br>
Zoltan<br>
<br>
<div class="moz-cite-prefix">On 2022-02-11 00:46, Allan López wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CABOeUQ8R-xz4+_mpzz5rFr3REf18S5tpcoqrL7=DBYbdWr2Y8w@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large">Yes, it
does. <br>
</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large"><br>
</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large">Thanks a
lot indeed. I am testing it.</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large"><br>
</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large">Best,</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large"><br>
</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large">Allan </div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">El jue, 10 feb 2022 a la(s)
15:19, Alexis R.L. (<a href="mailto:alroyliz0@gmail.com"
moz-do-not-send="true" class="moz-txt-link-freetext">alroyliz0@gmail.com</a>)
escribió:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">As far as I know v.voronoi.skeleton in gdal is
the closest thing we have that can do this in base QGIS.
<div><br>
</div>
<div>I hope this helps,</div>
<div><br clear="all">
<div>
<div dir="ltr">
<div dir="ltr">Alex</div>
</div>
</div>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">Le mer. 9 févr. 2022
à 17:57, Allan López <<a
href="mailto:allosa01@gmail.com" target="_blank"
moz-do-not-send="true" class="moz-txt-link-freetext">allosa01@gmail.com</a>>
a écrit :<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large">Dear
All, I need to calculate and display the center line
of an elongated river basin ( not the center of the
main river trunk) from a SHP.</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large"><br>
</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large">Thank's
in advance.</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large"><br>
</div>
<div class="gmail_default"
style="font-family:tahoma,sans-serif;font-size:large">Allan
Lopez</div>
</div>
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<br>
<pre class="moz-signature" cols="72">--
=============================================
Zoltan Szecsei GPrGISc 0031
Director, Geograph (Pty) Ltd.
GIS and Photogrammetric Services
Cape Town, South Africa.
Mobile: +27-83-6004028 (Signal, not WhatsApp)
<a class="moz-txt-link-abbreviated" href="http://www.geograph.co.za">www.geograph.co.za</a>
=============================================</pre>
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