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<p>Hello,</p>
<p>I have been trying to make some sense of the function
pgr_nodenetwork, but I haven't succeeded. <br>
</p>
<p>Based on the documentation, this function "Nodes an network edge
table.(...). What we mean by “noded” is that at every
intersection in the road network all the edges will be broken into
separate road segments"</p>
<p>I have been doing tests for the last couple of days. You can
reproduce a simple one, by executing the following SQL statements.
<br>
</p>
<p><br>
</p>
<p>-- Create test_graph table and insert two geometries<br>
</p>
<p>SET CLIENT_ENCODING TO UTF8;<br>
SET STANDARD_CONFORMING_STRINGS TO ON;<br>
BEGIN;<br>
CREATE TABLE "test_graph" (gid serial,<br>
"id" numeric(10,0),<br>
"nom" varchar(80));<br>
ALTER TABLE "test_graph" ADD PRIMARY KEY (gid);<br>
SELECT
AddGeometryColumn('','test_graph','geom','25831','LINESTRING',2);<br>
INSERT INTO "test_graph" ("id","nom",geom) VALUES
('3',NULL,'0102000020E764000008000000F281433F6B731A41C84583B869855141592275DD14731A41C89C7A7D73855141B3E5D70CD3721A4164B5681680855141BFC2A67BBE721A419A3856BE8585514137F861B0A1721A41D72C1EC58F855141D87C445995721A413DC21EB6968551416D2458939D721A41DFF4EFE89D85514137F861B0A1721A411578DD90A3855141');<br>
INSERT INTO "test_graph" ("id","nom",geom) VALUES
('5',NULL,'0102000020E76400000900000065D6DA5A51701A410D5914A88B855141DA9E3C70E5701A4106E8394987855141ADE2BBDC85711A415E9B857C85855141C32F009B0D721A416B2643758485514150B2FF8D78721A41A8C313B784855141BFC2A67BBE721A419A3856BE85855141930626E85E731A4135FA4C92888551414E90077728741A418D04908A90855141A5E6108797741A41F399907B97855141');<br>
COMMIT;<br>
ANALYZE "test_graph";<br>
<br>
-- Try to node the network.<br>
select pgr_nodenetwork ('test_Graph', 0.01, 'gid', 'geom');<br>
</p>
<p><br>
</p>
<p>You can see the geometries on images, before
(<a class="moz-txt-link-freetext" href="http://sigserver4.udg.edu/apps/original_geometries.png">http://sigserver4.udg.edu/apps/original_geometries.png</a>) and after
(<a class="moz-txt-link-freetext" href="http://sigserver4.udg.edu/apps/noded_geometries.png">http://sigserver4.udg.edu/apps/noded_geometries.png</a>), the noding
proces.</p>
<p>The result, is a set of 6 rows but the segments generated are not
the expected ones.</p>
<p>Does anyone know what's happening here?</p>
<p>Thanks for your help.<br>
</p>
<div class="moz-signature">-- <br>
<span style="font-size:8.5pt">
<b>Toni Hernández Vallès</b>
<br>
Servei de Sistemes d'Informació Geogràfica i Teledetecció<br>
-<br>
Universitat de Girona<br>
<b>SIGTE</b><br>
-<br>
Pl. Ferrater Mora 1<br>
17071 Girona<br>
Tel +34 972 418 039 (7026 intern)<br>
<a href="mailto:toni.hernandez@udg.edu">toni.hernandez@udg.edu</a>
<br>
<br>
<a href="http://www.sigte.udg.edu">http://www.sigte.udg.edu</a><br>
Twitter <a href="http://twitter.com/SIGTE_UDG">http://twitter.com/SIGTE_UDG</a><br>
<br>
</span></div>
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