[SOLVED] Mysterious parallel edges error

[imanvl]

Dear all,

I've just started using Gephi. Great software!

I've got a problem in reading in my data though and I hope somebody can help.

I've defined a gepx file but on reading it in, Gephi complains about parallel edges in my dynamic network. These are dropped leading to a loss of 70% of my edges. I've check my source data and have 0 parallel edges.

I exported the data that I just read in and I get

---------------

... output omitted ....

<edge id="e3171" source="157" target="158" weight="9.473476">
<attvalues>
<attvalue for="dynamicrange" value="1.0,1.0"/>

<edge id="e3173" source="7" target="1" weight="12827.1875">
<attvalues>
<attvalue for="dynamicrange" value="2.0,2.0"/>
</attvalues>

... output omitted ....

-------------------

As you can see e3172 is missing (as Gephi also told me reading in). In my original gefx file I have a line reading

<edge id="3173" source="6" target="1" weight="186506.09375" start="2" end="2"/>

The id is well behaved and runs from 1 to 109000. The node section has 158 nodes and node 1 and 6 exist in this period.

Why do I get the parallel edges error?
Why is the edge id value 3173 in my source gefx and am I missing e3172 in the Gephi? Why aren't these two the same?

Any and all hints and tips much appreciated.
Iman

[mbastian]

Sorry but I don't understand the problem, could you paste an sample gexf file with the issue so I can reproduce it ? Thanks

[imanvl]

Hi,

Below a stripped version of my data. I get my first "parallel edges" error in edge number 3173. This is also the first repeated edge (ie source=6 and target =1) but the date is different though so it seems Gephi doesn't pick up the date. For those edges that are read in, I do see the date in Data Laboratory. Hope this helps.

Best
Iman

<?xml version="1.0" encoding="UTF-8"?>
<gexf xmlns:viz="http:///www.gexf.net/1.1draft/viz" version="1.1" xmlns="http://www.gexf.net/1.1draft"
xmlns:xsi="http://www.w3.org/2001/XMLSchema??instance"
xsi:chemaLocation="http://www.gexf.net/1.1draft
http://www.gexf.net/1.1draft/gexf.xsd">
<meta lastmodifieddate="2009-11-08">
<creator>Iman van Lelyveld</creator>
<description>Network</description>
</meta>
<graph mode="dynamic" defaultedgetype="directed" timeformat="date">
start="1998-03-31" end="2009-01-01">
<nodes>
<node id="1" label="111" start="1998-03-31" end="2009-01-01"/>
<node id="2" label="118" start="1998-03-31" end="2009-01-01"/>
…
<node id="158" label="995" start="1998-03-31" end="2009-01-01"/>
</nodes>

<edges>
<edge id="1" source="6" target="1" weight="405767" start="1998-03-31" end="1998-04-01"/>
<edge id="2" source="11" target="1" weight="3952" start="1998-03-31" end="1998-04-01"/>
…
<edge id="3173" source="6" target="1" weight="39629" start="1998-06-30" end="1998-07-01"/>
…
<edge id="109051" source="151" target="158" weight="558071" start="2008-12-31" end="2009-01-01"/>
<edge id="109052" source="153" target="158" weight="133276" start="2008-12-31" end="2009-01-01"/>
</edges>
</graph>
</gexf>

[chrisg]

I suspect you will have better luck using the "spells" feature.
But I've not made use of it myself yet.

http://gexf.net/format/dynamics.html

If a node or an edge exists only at some timeranges, we use the concept of spells. Spells are not provided for data values, which are only limited by one start and one end

[galwarion]

<edges>
<edge id="1" source="6" target="1" weight="405767" start="1998-03-31" end="1998-04-01"/>
<edge id="2" source="11" target="1" weight="3952" start="1998-03-31" end="1998-04-01"/>
…
<edge id="3173" source="6" target="1" weight="39629" start="1998-06-30" end="1998-07-01"/>
…
<edge id="109051" source="151" target="158" weight="558071" start="2008-12-31" end="2009-01-01"/>
<edge id="109052" source="153" target="158" weight="133276" start="2008-12-31" end="2009-01-01"/>
</edges>

But you have parallel edges.

Code: Select all

<edge id="1" source="6" target="1" weight="405767" start="1998-03-31" end="1998-04-01"/>
<edge id="3173" source="6" target="1" weight="39629" start="1998-06-30" end="1998-07-01"/>

Unfortunately it looks like, that Gephi cant figure out edges from the same source to same target although its in different time... I have the same "problem". But spells or slices seem solving the problem for me... Thank you chrisg. I thought that it is possible to use them only with edges.

[mbastian]

Yeah you have to use spells. It's a good idea though, I added it to Ideas

[prempanigrahi]

Hi
I am also facing this parallel edge problem, when i try to run my program gephi 0.8.1 shows "Parallel edges are not supported yet, edge id='139' is ignored" , this way my 9 edges are ignored, difficult to continue the project. as i am doing a power grid project, and parallel edge is necessary . help me to continue my project with gephi.