Solving easy problems the hard way

There’s a charming little brain teaser that’s going around the Interwebs. It’s got various forms, but they all look something like this: This problem can be solved by pre-school children in 5-10 minutes, by programer – in 1 hour, by people with higher education … well, check … Continue reading

Shell scripting EC2 for fun and profit

Lately I’ve been doing some work with creating ad-hoc clusters of EC2 machines. My ultimate goal is to create a simple way to spin up a cluster of EC2 machines for use with Bryan Lewis’s very cool doRedis backend for the R foreach package. But that’s a whole other post. What I was … Continue reading

Fast Two Way Sync in Ubuntu!

I love the portability of a laptop. I have a 45 min train ride twice a day and I fly a little too, so having my work with me on my laptop is very important. But I hate doing long running analytics on my laptop when I’m in the office because it bogs down my laptop and all those videos on The … Continue reading

Where the heck has JD been?

It’s been pointed out to me that I haven’t had any blog posts in a while. It’s true. I’m fairly slack. But in the last few months I’ve changed jobs (same firm, new role), written an R abstraction on top of Hadoop, been to China, and managed to stay married. While that … Continue reading

Stochastic Simulation With Copulas in R

A friend of mine gave me a call last week and was wondering if I had a little R code that could illustrate how to do a Cholesky decomposition. He ultimately wanted to build a Monte Carlo model with correlated variables. I pointed him to a number of packages that do Cholesky decomp but then I … Continue reading