[jwp]

The non-friend vs anti-friend distinction didn't even occur to me, but it's clearly an important part of the experiment. I like all the discussion of data. Fun problem.

I did not realize squaring an adj matrix tells you what it does. Thanks for edjumacating me.

Did you go past f2hops? Seems like 3 would be reasonable and predictive. Since 1/2 of your tree is so small, and there were 12k nodes in the tree, that suggests to me a pretty easy task. Do you agree? It would be interesting to see if PCA or LDA pick the same features as the decision trees did. Just a click away in Weka, after all.

(An aside, and neat hack: Buddy of mine just walked in and saw the document on my screen. He saw the decision tree and said, "I remember those. In grad school I printed out decision trees as C if/else statements. Part of running my decision tree was a call to gcc.")

[adamsmith]

Hi jwp,

I think I tried or wanted to do f3hops. Either I did it and I was stretching the 2GB memory limit, or I couldn't. As you exponentiate the sparse matrix more and more you get a less and less sparse matrix. I was really hurting for memory.

Yeah, I really wish I could have spent more time exploring the algorithms side. If I didn't start Xobni during summer 2006 the plan was to write a book on machine learning, in practice. One of these days..

P.S. Would love to get in touch. Can you post your email or send me a note? My email is adam dot smith foo xobni.com where foo == @.