Book Image

Python Machine Learning By Example - Third Edition

By : Yuxi (Hayden) Liu
Book Image

Python Machine Learning By Example - Third Edition

By: Yuxi (Hayden) Liu

Overview of this book

Python Machine Learning By Example, Third Edition serves as a comprehensive gateway into the world of machine learning (ML). With six new chapters, on topics including movie recommendation engine development with Naïve Bayes, recognizing faces with support vector machine, predicting stock prices with artificial neural networks, categorizing images of clothing with convolutional neural networks, predicting with sequences using recurring neural networks, and leveraging reinforcement learning for making decisions, the book has been considerably updated for the latest enterprise requirements. At the same time, this book provides actionable insights on the key fundamentals of ML with Python programming. Hayden applies his expertise to demonstrate implementations of algorithms in Python, both from scratch and with libraries. Each chapter walks through an industry-adopted application. With the help of realistic examples, you will gain an understanding of the mechanics of ML techniques in areas such as exploratory data analysis, feature engineering, classification, regression, clustering, and NLP. By the end of this ML Python book, you will have gained a broad picture of the ML ecosystem and will be well-versed in the best practices of applying ML techniques to solve problems.
Table of Contents (17 chapters)
15
Other Books You May Enjoy
16
Index

Estimating with linear regression

The first regression model that comes to our mind is linear regression. Does it mean fitting data points using a linear function, as its name implies? Let's explore it.

How does linear regression work?

In simple terms, linear regression tries to fit as many of the data points as possible with a straight line in two-dimensional space or a plane in three-dimensional space. It explores the linear relationship between observations and targets, and the relationship is represented in a linear equation or weighted sum function. Given a data sample x with n features, x1, x2, …, xn (x represents a feature vector and x = (x1, x2, …, xn)), and weights (also called coefficients) of the linear regression model w (w represents a vector (w1, w2, …, wn)), the target y is expressed as follows:

Also, sometimes the linear regression model...