Book Image

Hands-On Machine Learning with scikit-learn and Scientific Python Toolkits

By : Tarek Amr
Book Image

Hands-On Machine Learning with scikit-learn and Scientific Python Toolkits

By: Tarek Amr

Overview of this book

Machine learning is applied everywhere, from business to research and academia, while scikit-learn is a versatile library that is popular among machine learning practitioners. This book serves as a practical guide for anyone looking to provide hands-on machine learning solutions with scikit-learn and Python toolkits. The book begins with an explanation of machine learning concepts and fundamentals, and strikes a balance between theoretical concepts and their applications. Each chapter covers a different set of algorithms, and shows you how to use them to solve real-life problems. You’ll also learn about various key supervised and unsupervised machine learning algorithms using practical examples. Whether it is an instance-based learning algorithm, Bayesian estimation, a deep neural network, a tree-based ensemble, or a recommendation system, you’ll gain a thorough understanding of its theory and learn when to apply it. As you advance, you’ll learn how to deal with unlabeled data and when to use different clustering and anomaly detection algorithms. By the end of this machine learning book, you’ll have learned how to take a data-driven approach to provide end-to-end machine learning solutions. You’ll also have discovered how to formulate the problem at hand, prepare required data, and evaluate and deploy models in production.
Table of Contents (18 chapters)
1
Section 1: Supervised Learning
8
Section 2: Advanced Supervised Learning
13
Section 3: Unsupervised Learning and More

Homogenizing the columns' scale

Different numerical columns may have different scales. One column's age is in the tens, while its salary is typically in the thousands. As we saw earlier, putting different columns into a similar scale helps in some cases. Here are some of the cases where scaling is recommended:

  • It allows gradient-descent solvers to converge quicker.
  • It is needed for algorithms such as KNN and Principle Component Analysis (PCA)
  • When training an estimator, it puts the features on a comparable scale, which helps when juxtaposing their learned coefficients.

In the next sections, we are going to examine the most commonly used scalers.

The standard scaler

This converts the features into normal distribution by setting their mean to 0 and their standard deviation to 1. This is done using the following operation, where a column's mean value is subtracted from each value in it, and then...