In this chapter, you will learn the basics of classification models, and how they can be used in a variety of contexts. Classification generically refers to classifying things into distinct categories or classes. In the case of a classification model, we typically wish to assign classes based on a set of features. The features might represent variables related to an item or object, an event or context, or some combination of these.
The simplest form of classification is when we have two classes; this is referred to as binary classification. One of the classes is usually labeled as the positive class (assigned a label of 1), while the other is labeled as the negative class (assigned a label of -1, or, sometimes, 0). A simple example with two classes is shown in the following figure. The input features, in this case, have two dimensions, and the feature values are represented...
