change colour of links/ties over time

[keuchenius8]

Hi all,

I am just starting to work with Gephi, but Im under time pressure so first like to see if what I aim to do is possible (and not too time consuming).

With data stored in mysql database I like to create a network on which I dynamically show diffusion/spread. This means that I need not only nodes to change colour over time ( Ive been reading that is possible) but I also need to set time intervals for the edges and their colours.

This way I hope to visualise how one node becomes 'activated' (with colour) and then infects his neighbours, via the links (that thus also change colour)! It is important that the links change colour too, since if node A is infected and his neighbour B gets infected later, this is not always caused by the link between them, sometimes the colours hence needs not to change.

Hope someone can simply tell me if this is do-able, and perhaps redirect me to the right page!!
thanks a lot!

[seinecle]

Hi,

I don't think color attributes can be set dynamically in a gexf file, which is the standard format in gephi to represent dynamic networks. Only the weight (thickness) of the edge can be set to evolve in time intervals.
If you see dynamic networks in Gephi with changing colors of edges and nodes, this effect is obtained with a ranking operation: a changing numerical value in the attribute of an edge (say: attribute "data transmitted") is translated in the corresponding color gradient. Ex: low values of the attribute =blue, high values = red. That might be fine with you, or maybe that your values correspond to qualitative attributes no fitting this gradient logic.

If that is fine with you, I'd suggest using py4gexf, rgexf of gexf4j to generate a network file containing all the dynamics you need. This type of file can then be opened with Gephi and read with the timeline.

Best,

Clement

[keuchenius8]

thanks!
So it seems possible; just determine for each link when it should ' change ' colour, and translate this into a change in value of the ' data transmitted' attribute (that I should create).

I use data from a postgresql database that I export as a csv file. Until now that was working well, also with dynamic data. I havent been working with attributes yet, but I assume the method Im using now should be working fine for attributes as well?!

thanks!

I