Book Image

Mastering Machine Learning with scikit-learn - Second Edition

By : Gavin Hackeling
Book Image

Mastering Machine Learning with scikit-learn - Second Edition

By: Gavin Hackeling

Overview of this book

Machine learning is the buzzword bringing computer science and statistics together to build smart and efficient models. Using powerful algorithms and techniques offered by machine learning you can automate any analytical model. This book examines a variety of machine learning models including popular machine learning algorithms such as k-nearest neighbors, logistic regression, naive Bayes, k-means, decision trees, and artificial neural networks. It discusses data preprocessing, hyperparameter optimization, and ensemble methods. You will build systems that classify documents, recognize images, detect ads, and more. You will learn to use scikit-learn’s API to extract features from categorical variables, text and images; evaluate model performance, and develop an intuition for how to improve your model’s performance. By the end of this book, you will master all required concepts of scikit-learn to build efficient models at work to carry out advanced tasks with the practical approach.
Table of Contents (22 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
9
From Decision Trees to Random Forests and Other Ensemble Methods
Index

The perceptron


Invented by Frank Rosenblatt at the Cornell Aeronautical Laboratoryin the late 1950s, the development of the perceptron was originally motivated by efforts to simulate the human brain. A brain is composed of cells calledneuronsthat process information, and connections between neurons are calledsynapses, through which information is transmitted. The human brain has been estimated to be composed of as many as 100 billion neurons and 100 trillion synapses. Illustrated in the following image, the main components of a neuron are dendrites, a body, and an axon. The dendrites receive electrical signals from other neurons. The signals are processed in the neuron's body, which then sends a signal through the axon to another neuron.

An individual neuron can be thought of as a computational unit that processes one or more inputs to produce an output. A perceptron functions analogously to a neuron; it accepts one or more inputs, processes them, and returns an output. It may seem that a...