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

Section 3 – Modeling Continuous Targets with Supervised Learning

The final ten chapters of this book introduce a wide range of machine learning algorithms, for predicting both continuous or categorical targets, or when there is no target. We explore models for continuous targets in this chapter.

A persistent theme in these chapters is that finding the best possible model is partly about balancing variance and bias. When our models fit the training data too well, they may not be as generalizable as we need them to be. In cases like that, they may have low bias but high variance. For each algorithm we examine in these chapters, we discuss strategies for achieving this balance. These strategies range from regularization for linear regression and support vector regression models, to the value of k for k-nearest neighbors, to the maximum depth of decision trees.

We also get a chance to practice the preprocessing, feature selection, and model evaluation strategies we worked...