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 SVM

Let's consider a dataset of feature vectors we want to classify:

For simplicity, we assume we are working with a bipolar classification (in all the other cases, it's possible to automatically use the one-versus-all strategy) and we set our class labels as -1 and 1:

Our goal is to find the best separating hyperplane, for which the equation is as follows:

In the following graph, there's a bidimensional representation of such a hyperplane:

Structure of a linear SVM bipolar problem

In this way, our classifier can be written as follows:

In a realistic scenario, the two classes are normally separated by a margin with two boundaries where a few elements lie. Those elements are called support vectors and the algorithm's name derives from their peculiar role. For a more generic mathematical expression, it's preferable to renormalize our dataset...