Classifying using logarithmic regression

Logarithmic regression solves a different problem from ordinary linear regression. It is commonly used for classification problems where, typically, we wish to classify data into two distinct groups, according to a number of predictor variables. Underlying this technique is a transformation that’s performed using logarithms. The original classification problem is transformed into a problem of constructing a model for the log-odds. This model can be completed with simple linear regression. We apply the inverse transformation to the linear model, which leaves us with a model of the probability that the desired outcome will occur, given the predictor data. The transform we apply here is called the logistic function, which gives its name to the method. The probability we obtain can then be used in the classification problem we originally aimed to solve.

In this recipe, we will learn how to perform logistic regression and use this technique...