<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>Hi,</p>
<p>You could consider <a class="moz-txt-link-freetext" href="https://networkx.org/">https://networkx.org/</a> if you are really
looking for just a graph. It's a pure Python library but it's not
included with QGIS. It's not too difficult to learn but geared
towards analysis and not visualization like Graphviz. (I have
never user Graphviz so don't take my word for it.)</p>
<p>You can still do what you want in QGIS. Shapefile lines could
simplified by changing the geometry into a simple line between the
first and last node. Qgis has the advantage (and disadvantage if
the network is complicated) of giving you complete control on were
you position nodes on a map. Graph libraries usually give you a
choice of rendering styles but it gets complicated if you want
complete control on the rendering. You could also use QGIS to
draw the shapefile and export those to Graphviz for
visualization. You could also look at Cytoscape and Gephi that
seem to be vizualisation software for graphs.<br>
</p>
<p><a class="moz-txt-link-freetext" href="https://gephi.org/">https://gephi.org/</a></p>
<p><a class="moz-txt-link-freetext" href="https://cytoscape.org/">https://cytoscape.org/</a><br>
</p>
<p>Nicolas<br>
</p>
<div class="moz-cite-prefix">On 2021-02-10 11:39 a.m., chris
hermansen wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CACc2_6_xN9B10sK6_Pnxpy5vYTYmJBXAE2Me8VBeK=ndUxa-bw@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">
<div dir="ltr">Giacomo and list,<br>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Wed, Feb 10, 2021 at 4:05
AM Giacomo Uguccioni <<a
href="mailto:giacomo.uguccioni@gmail.com"
moz-do-not-send="true">giacomo.uguccioni@gmail.com</a>>
wrote:<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">Thanks a lot! <br>
<div>I would like to represent a shapefile or more
shapefiles of nodes and connections (lines and points)</div>
<div>in a layout similar to an electrical scheme, a
symbolic and conceptual scheme and not a geographical
one.<br>
</div>
<div>I attached an image with qgis view and output that I
would like to get.</div>
</div>
<br>
</blockquote>
<div><br>
</div>
<div>In your graph representation (version to the right in
your sketch) how do you determine that A is the start node?
(and not 3 or 4?)</div>
<div><br>
</div>
<div>This kind of diagram is what Graphviz is built to
represent. You will need to convert your shapefiles to a
Graphviz input program. A reasonable starting approach
might be to use some vector operations to get attribute
tables that look like [from-node,to-node] along with the
node attributes. I suggest you study the Graphviz
documentation, which is quite excellent and full of worked
examples, to see how to draw the sketch you presented here,
and then revisit your shapefiles to think about how to
convert them to that format.<br>
</div>
</div>
<br clear="all">
<br>
-- <br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">Chris Hermansen · clhermansen "at" gmail "dot"
com<br>
<br>
C'est ma façon de parler.</div>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
Qgis-user mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Qgis-user@lists.osgeo.org">Qgis-user@lists.osgeo.org</a>
List info: <a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/qgis-user">https://lists.osgeo.org/mailman/listinfo/qgis-user</a>
Unsubscribe: <a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/qgis-user">https://lists.osgeo.org/mailman/listinfo/qgis-user</a>
</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
Nicolas Cadieux
<a class="moz-txt-link-freetext" href="https://gitlab.com/njacadieux">https://gitlab.com/njacadieux</a></pre>
</body>
</html>