Book Image

Mastering Machine Learning Algorithms

Book Image

Mastering Machine Learning Algorithms

Overview of this book

Machine learning is a subset of AI that aims to make modern-day computer systems smarter and more intelligent. The real power of machine learning resides in its algorithms, which make even the most difficult things capable of being handled by machines. However, with the advancement in the technology and requirements of data, machines will have to be smarter than they are today to meet the overwhelming data needs; mastering these algorithms and using them optimally is the need of the hour. Mastering Machine Learning Algorithms is your complete guide to quickly getting to grips with popular machine learning algorithms. You will be introduced to the most widely used algorithms in supervised, unsupervised, and semi-supervised machine learning, and will learn how to use them in the best possible manner. Ranging from Bayesian models to the MCMC algorithm to Hidden Markov models, this book will teach you how to extract features from your dataset and perform dimensionality reduction by making use of Python-based libraries such as scikit-learn v0.19.1. You will also learn how to use Keras and TensorFlow 1.x to train effective neural networks. If you are looking for a single resource to study, implement, and solve end-to-end machine learning problems and use-cases, this is the book you need.
Table of Contents (22 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
13
Deep Belief Networks
Index

Summary


In this chapter, we introduced the main concepts of ensemble learning, focusing on both bagging and boosting techniques. In the first section, we explained the difference between strong and weak learners and we presented the big picture of how it's possible to combine the estimators to achieve specific goals.

The next topic focused on the properties of decision trees and their main strengths and weaknesses. In particular, we explained that the structure of a tree causes a natural increase in the variance. The bagging technique called random forests allow mitigating this problem, improving at the same time the overall accuracy. A further variance reduction can be achieved by increasing the randomness and employing a variant called extra randomized trees. In the example, we have also seen how it's possible to evaluate the importance of each input feature and perform dimensionality reduction without involving complex statistical techniques.

In the third section, we presented the most...