Machine Learning Using Decision Trees in Ruby

In earlier articles we demonstrated how simple distance metrics and a nearest-neighbour recommendation system could be implemented in ruby. We will stick with this machine learning (ML) theme in the present article and discuss the implementation of a simple decision tree algorithm, again in ruby.We will implement a decsion tree ML algorithm and we will then train our model with data for a classification task. Once trained, our decision tree model should be able to predict the classification for previously unseen data. We will use a simple dataset as we develop the algorithm, but we will also demonstrate how the algorithm can then be applied to a more challenging problem.The algorithms implemented in this article are inspired by the python versions presented by Toby Segaran in Collective Intelligence (Amazon), which I highly recommend for anyone interested in learning the fundamentals of classic machine learning methods.