
Hi Team,
Firstly big kudos to NodeXL team as always  loving it and all the recent developments!
Is there any current functionality or planned functionality for layout algorithm that accomodates weighted edges in the layout so there are unequal forces between nodes based on edge weight?
All the best,
Daniel



As a matter of fact, yes. I will be modifying the FruchtermanReingold layout to respect an optional Edge Weight column on the Edges worksheet so that edges with higher weight will exert stronger attractive forces on their vertices. I'm not sure
if it will be in the next release (around October 27) or the one after that (about two weeks later).
If you want to be notified of new NodeXL releases, go to the Downloads tab at
http://nodexl.codeplex.com/releases and look for "Release Notification."
 Tony



Hi Tony,
Great news! Are there also any plans / possibilities for applying a clustering algorithm that respects the edge weights?
Many thanks,
Daniel
Sent from my iPhone
From: tcap479
As a matter of fact, yes. I will be modifying the FruchtermanReingold layout to respect an optional Edge Weight column on the Edges worksheet so that edges with higher weight will exert stronger attractive forces on their vertices. I'm not sure if it will
be in the next release (around October 27) or the one after that (about two weeks later).
If you want to be notified of new NodeXL releases, go to the Downloads tab at
http://nodexl.codeplex.com/releases and look for "Release Notification."
 Tony



Daniel:
The FruchtermanReingold change will be in the next release, due out sometime this week. Changes to the clustering algorithms might be in the following release (two weeks later), depending on how difficult they are to modify.
 Tony



Awesome Thank you Tony!
Sent from my iPhone
From: tcap479
Daniel:
The FruchtermanReingold change will be in the next release, due out sometime this week. Changes to the clustering algorithms might be in the following release (two weeks later), depending on how difficult they are to modify.
 Tony



Hi Tony,
Has there been any progress with these developments? Could'nt spot them in recent releases.
Many thanks,
Daniel


Coordinator
Jan 15, 2012 at 3:17 PM

We have not yet implemented edge strength aware clustering. The FruchtermanReingold layout now does respect edge weights.
1.0.1.193 (20111027)
 The FruchtermanReingold layout algorithm now uses an optional Edge Weight column on the Edges worksheet to determine the attractive forces between vertices. An edge with a larger Edge Weight exerts a greater attractive force on its vertices. Edge Weight
values should be greater than zero. A value of zero or less is ignored and 1.0 is used instead.
Regards,
Marc



How do I use the Edg Weight in code? I tried to set the weight when I create the edges like this:
e.SetValue(ReservedMetadataKeys.EdgeWeight, Math.Abs(item.RelationshipValue));
My RelationShipValue is a correlation coefficient between 0.7 and 1. I couldn't really see a difference in the resulting graphs. Do I have to set a special flag for the FruchtermanReingold layout to take the EdgeWeight into account?
Thanks
Jan



Jan,
No, it should just work. The results vary widely with the graph and the edge weights involved. Your particular range of edge weights is not very large, which I'm guessing is why you're not seeing much of an effect. You might try transforming
your edge weights to a larger range.
 Tony



Hi Tony,
I just tried some transformation and I can see some difference. But here is very simple example where I can't see the weigth being applied.
https://dlweb.dropbox.com/get/Photos/screenshots/network_0002_C3ADR1.png?w=9fd7a2d9
Here the correlation values between those vertice:
Ps_Amax_10 Ps_Transpiration_10 0.702512400400152
Ps_Amax_10 Ps_Conductance_10 0.700119863655117
Ps_Conductance_10 Ps_Transpiration_10 0.998936745166694
I also do scaling of the alpha channel of the edges. So I would expect shorter darker edges and longer lighter edges in my graphs.
Cheers
Jan



Hi Tony,
which clustering algorithm takes teh edge weight into account?
Cheers
Jan



Jan:
I can't get to your file and I don't understand what your correlation values mean, but if you'd like to post a simple problematic edge list with edge weights that don't seem to be working for you, I can try those edges in our Excel Template and try to see
what's going on.
When I try this simple edge list in the Excel Template, edge CD is much shorter than edge AB, as expected:
A, B, 1
C, D, 100
 Tony



Jan:
Unfortunately, none of our clustering algorithms currently take edge weight into account.
 Tony



This link should work.
http://dl.dropbox.com/u/32658643/screenshots/network_0002_C3ADR1.png
1 : 100 is a pretty large scale. So what would be a good scale have a nice effect on the layout. Correlation values are never bigger than 1.



Try some experiments, starting with 1:100.
 Tony

