Programming Machine Learning

Chapter 5A Discerning Machine

We started our journey in machine learning by way of linear regression. Now we’re going to use that knowledge (and that code) to branch off toward our goal: a program that recognizes images.

This chapter covers the first step toward image recognition. We’ll build a classifier—a program that assigns data to one of a limited number of classes. Instead of numerical labels, classifiers work with categorical labels. As an example, consider the difference betwen our pizza predictor and a system that recognizes plants. The pizza predictor outputs a number. By contrast, the plant classifier would output the name of a plant, taken from a predefined list of possible species.

In this chapter, we’ll start off small: our classifier ...