Book Image

Machine Learning Algorithms - Second Edition

Book Image

Machine Learning Algorithms - Second Edition

Overview of this book

Machine learning has gained tremendous popularity for its powerful and fast predictions with large datasets. However, the true forces behind its powerful output are the complex algorithms involving substantial statistical analysis that churn large datasets and generate substantial insight. This second edition of Machine Learning Algorithms walks you through prominent development outcomes that have taken place relating to machine learning algorithms, which constitute major contributions to the machine learning process and help you to strengthen and master statistical interpretation across the areas of supervised, semi-supervised, and reinforcement learning. Once the core concepts of an algorithm have been covered, you’ll explore real-world examples based on the most diffused libraries, such as scikit-learn, NLTK, TensorFlow, and Keras. You will discover new topics such as principal component analysis (PCA), independent component analysis (ICA), Bayesian regression, discriminant analysis, advanced clustering, and gaussian mixture. By the end of this book, you will have studied machine learning algorithms and be able to put them into production to make your machine learning applications more innovative.
Table of Contents (19 chapters)

Linear classification

Let's consider a generic linear classification problem with two classes. In the following graph, there's an example:

Bidimensional scenario for a linear classification problem

Our goal is to find an optimal hyperplane, that separates the two classes. In multi-class problems, the one-vs-all strategy is normally adopted, so the discussion can focus only on binary classifications. Suppose we have the following dataset made up of n m-dimensional samples:

This dataset is associated with the following target set:

Generally, there are two equivalent options; binary and bipolar outputs and different algorithms are based on the former or the latter without any substantial difference. Normally, the choice is made to simplify the computation and has no impact on the results.

We can now define a weight vector made of m continuous components:

We can also...