I am still working my way through “Machine Learning in Action”, converting the samples from Python to F#. I am currently in the middle of chapter 6, dedicated to Support Vector Machines, which has given me more trouble than the previous ones. This post will be sharing my current progress: the code I have so far is a working translation of the naïve SVM implementation, presented in the first half of the chapter. We’ll get to kernels, and the full Platt SMO algorithm in a later post – today will be solely di[...]

The Kaggle/StackOverflow contest officially closed a few days ago, which makes it a perfect time to have a miniature retrospective on that experience. The objective of the contest was to write an algorithm to predict whether a StackOverflow question would be closed by moderators, and the reason why. The contest was announced just a couple of days before what was supposed to be 4 weeks of computer-free vacation travelling around Europe. Needless to say, a quick change of plans followed; I am a big fan of S[...]

This post is to be filed in the “useless but fun” category. A friend of mine was doing some Hadoopy stuff a few days ago, experimenting with rather large sparse matrices and their products. Long story short, we ended up wondering how sparse the product of 2 sparse matrices should be. A sparse matrix is a matrix which is primarily filled with zeros. The product of two matrices involves computing the dot product of each row of the first one, with each column of the second one. There is clearly a relationship[...]

It’s been forever since I last posted, I worked quite a bit on PezHack and then stopped for a while.  I’m back to it now.  In this post I will describe a technique I used to greatly reduce the amount of code and abstract away some repetitive imperative code. The Problem PezHack is a turn based game. The screen does not re-render itself all the time like a real-time game, but only when something changes and at the end of a the player’s turn.  The agent-based approach I used to separate the various sub syste[...]

In this post, we are going to create a Converter class who converts values to strings. The conversion rules are specified by passing the name of a culture to the class’ constructor. The culture name can contain just the language (as ISO 639-1 alpha-2 code, e. g. “en”) or the language and region (as ISO 3166 code, e. g. “US”) combined with hyphen, e. g. “en-US”. An empty culture name “” specifies the invariant culture, which falls back to “en”. The class has only one conversion method ToString, who is generi[...]