Book Image

Data Cleaning and Exploration with Machine Learning

By : Michael Walker
Book Image

Data Cleaning and Exploration with Machine Learning

By: Michael Walker

Overview of this book

Many individuals who know how to run machine learning algorithms do not have a good sense of the statistical assumptions they make and how to match the properties of the data to the algorithm for the best results. As you start with this book, models are carefully chosen to help you grasp the underlying data, including in-feature importance and correlation, and the distribution of features and targets. The first two parts of the book introduce you to techniques for preparing data for ML algorithms, without being bashful about using some ML techniques for data cleaning, including anomaly detection and feature selection. The book then helps you apply that knowledge to a wide variety of ML tasks. You’ll gain an understanding of popular supervised and unsupervised algorithms, how to prepare data for them, and how to evaluate them. Next, you’ll build models and understand the relationships in your data, as well as perform cleaning and exploration tasks with that data. You’ll make quick progress in studying the distribution of variables, identifying anomalies, and examining bivariate relationships, as you focus more on the accuracy of predictions in this book. By the end of this book, you’ll be able to deal with complex data problems using unsupervised ML algorithms like principal component analysis and k-means clustering.
Table of Contents (23 chapters)
1
Section 1 – Data Cleaning and Machine Learning Algorithms
5
Section 2 – Preprocessing, Feature Selection, and Sampling
9
Section 3 – Modeling Continuous Targets with Supervised Learning
13
Section 4 – Modeling Dichotomous and Multiclass Targets with Supervised Learning
19
Section 5 – Clustering and Dimensionality Reduction with Unsupervised Learning

Key concepts of SVR

We will start this section by discussing how support vector machines are used for classification. We will not go into much detail here, leaving a detailed discussion of support vector classification to Chapter 13, Support Vector Machine Classification. But starting with support vector machines for classification will lead nicely to an explanation of SVR.

As I discussed at the beginning of this chapter, support vector machines find the hyperplane that maximizes the margin between classes. When there are only two features present, that hyperplane is just a line. Consider the following example plot:

Figure 8.1 – Support vector machine classification based on two features

The two classes in this diagram, represented by red circles and blue squares, are linearly separable using the two features, x1 and x2. The bold line is the decision boundary. It is the line that is furthest away from border data points for each class, or the maximum...