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

Using bagging regressors

We will go back to the Automobile dataset as we are going to use the bagging regressor this time. The bagging meta-estimator is very similar to random forest. It is built of multiple estimators, each one trained on a random subset of the data using a bootstrap sampling method. The key difference here is that although decision trees are used as the base estimators by default, any other estimator can be used as well. Out of curiosity, let's use the K-Nearest Neighbors (KNN) regressor as our base estimator this time. However, we need to prepare the data to suit the new regressor's needs.

Preparing a mixture of numerical and categorical features

It is recommended to put all features on the same scale when using distance-based algorithms such as KNN. Otherwise, the effect of the features with higher magnitudes on the distance metric will overshadow the other features. As we have a mixture of numerical and categorical features here...