precision-recall-curve

In this post, I am going to talk about the different metrics that we can use to measure classifier performance when we are dealing with unbalanced data.Before defining any metric let’s talk a little bit about what an unbalanced dataset is, and the problems we might face when dealing with this kind of data. In Machine Learning, when we talk about data balance we are referring to the number of instances among the different classes in our dataset, there are two cases.Balanced dataWhen it comes to the distribution of classes in a dataset there could be several scenarios depending on the proportion of instances in each class. Let’s look an example using a binary dataset.Class distribution reference ImageThe figure above illustrates the feature distribution of two different classes, As it can be...