Data Visualization: Plotting friendship relations

Question

I guess those who have worked in communities and social networks might have some experience in this.

I am trying to plot a graph of all the friendships that exists on my site and in doing so identify clusters of strongly interconnected users.

Does anyone have any experience in doing something like this? Also, does SQL Server 2008 BI have tools that allows for this type of modelling?

Thanks

Answer 1

Programming Collective Intelligence's chapter 5 is dedicated to optimization and network visualization. Using the modules available here and the snippet below, I could make the following image:

>>> import optimization
>>> import socialnetwork
>>> sol = optimization.annealingoptimize(socialnetwork.domain, socialnetwork.crosscount, step=50, cool=0.99)
>>> socialnetwork.drawnetwork(sol)

The advantages of this approach is that you can easily change the cost function, use different optimization algorithms, or use another library to view the solution.

Answer 2

Take a look at neato from the Graphviz command line tool suite. AS input it takes a so called .dot file. The format is straight forward you should just be able to iterate over all friendship relations in your system and write them into the file.

Answer 3

For inspiration, take a look at these social graphs from "Visual Complexity" collection.

Many visualizations have explanatory papers and articles mentioning graphing tools, libraries and algorithms used to obtain the images.

Examples from "Social Networks" category:

Answer 4

Your graph will be probably reasonably large, so GraphViz is a poor choice. It does a nice job for tiny graphs, but not for huge ones. I'd recommend that you try aiSee instead (here are some example graphs). It requires graphs to be specified in a simple human-readable format called GDL.

_{(source: aisee.com)}

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Sample social network http://www.aisee.com/graph_of_the_month/pubmed5.gif

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_{(source: aisee.com)}