Machine Learning in Java - Second Edition

Solving problems with machine learning

Among the different machine learning approaches, there are three main ways of learning, as shown in the following list:

• Supervised learning
• Unsupervised learning
• Reinforcement learning

Given a set of example inputs X, and their outcomes Y, supervised learning aims to learn a general mapping function f, which transforms inputs into outputs, as f: (X,Y).

An example of supervised learning is credit card fraud detection, where the learning algorithm is presented with credit card transactions (matrix X) marked as normal or suspicious (vector Y). The learning algorithm produces a decision model that marks unseen transactions as normal or suspicious (this is the f function).

In contrast, unsupervised learning ...