Tool to analyze user response patterns

FYI: Mostly for my own amusement, I've been working on ways to analyze Reddit behavior. Among the tools I've been developing is a way to look at user response patterns: statistics on who responds to whom.

These images illustrate what I'm trying to do. Each network shows user response patterns within a specific subreddit. An arrow from user #1 to user #2 indicates that the total karma (within the subreddit for the data set at hand) from comments where user #1 responds to user #2 is greater than a given threshold. Note that this analysis includes responses to original posts, although I have made it easy to exclude original posts if desired.

If you have a question about a sub or post that this analysis could help answer, I'm willing to use your question as a test case. PM me or respond to this OP. It may take me a few days to get back to you, depending on how busy I am with bill-paying activities.