[SOLVED] parallel edges

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weedlili
Posts: 11
Joined: 03 May 2011 15:02

[SOLVED] parallel edges

Post by weedlili » 04 May 2011 08:30

Hello,

Is there a way that Gephi ignore parallel edges? I would prevent it from increasing the edge's weight during the import when parallel edges are found.

Thanks !

W.

admin
Gephi Community Manager
Posts: 964
Joined: 09 Dec 2009 14:41

Re: parallel edges

Post by admin » 04 May 2011 09:19

No,

But you can set edge weight to 1 in the Data Laboratory. In Edges > Fill Column with a value (on the bottom) > Weight

weedlili
Posts: 11
Joined: 03 May 2011 15:02

Re: parallel edges

Post by weedlili » 04 May 2011 09:59

Unfortunately I cannot see the column "weight" in the Edges list, even if all attributes columns that can be shown are ticked.
Weight is nevertheless displayed when I edit an edge.

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mbastian
Gephi Architect
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Location: San Francisco, CA

Re: parallel edges

Post by mbastian » 04 May 2011 16:03

Is there a way that Gephi ignore parallel edges? I would prevent it from increasing the edge's weight during the import when parallel edges are found.
Yes by default it merges the edge weight.
Unfortunately I cannot see the column "weight" in the Edges list, even if all attributes columns that can be shown are ticked.
That is weird, is that for all graphs or just this one?

weedlili
Posts: 11
Joined: 03 May 2011 15:02

Re: parallel edges

Post by weedlili » 04 May 2011 17:58

Just for this one. I checked with previous graphs and weights were correctly displayed (regardless of the presence of parallel edges or not).

I re-opened the problematic graph and got the following error : "the project file couldn't be opened. Please check the file has .gephi extension. IllegalArgumentException - the value column doesn't exist".

Actually it opens anyway,, diplaying edges... :?: Thus I can work on it, but this is weird!

admin
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Joined: 09 Dec 2009 14:41

Re: parallel edges

Post by admin » 19 May 2011 13:50

I have the opposite issue:

I import an edge list, edges having different attributes hence they are not merged, which is good. But in the Overview I'd like to see the thickness of the edges proportional to the sum of the edge weights it represent, like meta-edges.

Is it something we could implement?

Or does it make sense to add a way to group edges and not only nodes in the Data Lab?

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mbastian
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Re: parallel edges

Post by mbastian » 19 May 2011 16:32

Yeah, but you can already do that with merge, no?

Go to Merge Columns, pick your weights columns and take the SUM operator?

admin
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Re: parallel edges

Post by admin » 19 May 2011 16:57

No because I would want to merge rows, not columns, and there is no way to merge either nodes or edges in Gephi :)

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mbastian
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Joined: 10 Dec 2009 10:11
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Re: parallel edges

Post by mbastian » 19 May 2011 22:20

Not sure I understand, can you explain or show some of your data?

admin
Gephi Community Manager
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Re: parallel edges

Post by admin » 20 May 2011 09:47

Ah damn it, when I use the "Import Spreadsheet" in the Data Lab, it only imports the first edge, the others are ignored. Imagine an edge list:

Code: Select all

"ID"	"Source"	"Target"	"AnAttribute"
0	1	2	attrvalue0
1	1	2	attrvalue1
Only the first edge will be imported, the second is ignored. Sorry for my mistake.

In a case of parallel edges, I suggest to warn the user and make the "Import Spreadsheet" to behave like the CSV File Importer do by summing the weights if possible, and leave blank the other attributes. I open a bug.

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