Book Image

Hands-On Ensemble Learning with Python

By : George Kyriakides, Konstantinos G. Margaritis
Book Image

Hands-On Ensemble Learning with Python

By: George Kyriakides, Konstantinos G. Margaritis

Overview of this book

Ensembling is a technique of combining two or more similar or dissimilar machine learning algorithms to create a model that delivers superior predictive power. This book will demonstrate how you can use a variety of weak algorithms to make a strong predictive model. With its hands-on approach, you'll not only get up to speed with the basic theory but also the application of different ensemble learning techniques. Using examples and real-world datasets, you'll be able to produce better machine learning models to solve supervised learning problems such as classification and regression. In addition to this, you'll go on to leverage ensemble learning techniques such as clustering to produce unsupervised machine learning models. As you progress, the chapters will cover different machine learning algorithms that are widely used in the practical world to make predictions and classifications. You'll even get to grips with the use of Python libraries such as scikit-learn and Keras for implementing different ensemble models. By the end of this book, you will be well-versed in ensemble learning, and have the skills you need to understand which ensemble method is required for which problem, and successfully implement them in real-world scenarios.
Table of Contents (20 chapters)
Free Chapter
1
Section 1: Introduction and Required Software Tools
4
Section 2: Non-Generative Methods
7
Section 3: Generative Methods
11
Section 4: Clustering
13
Section 5: Real World Applications

Creating forests

By creating a number of trees using any valid randomization method, we have essentially created a forest, hence the algorithm's name. After generating the ensemble's trees, their predictions must be combined in order to have a functional ensemble. This is usually achieved through majority voting for classification problems and through averaging for regression problems. There are a number of hyperparameters associated with Random Forests, such as the number of features to consider at each node split, the number of trees in the forest, and the individual tree's size. As mentioned earlier, a good starting point for the number of features to consider is as follows:

  • The square root of the number of total features for classification problems
  • One-third of the number of total features for regression problems

The total number of trees can be fine-tuned...