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

Naïve Bayes classification models

One of the attractions of naïve Bayes is that you can get decent results quickly, even when you have lots of data. Both fitting and predicting are fairly easy on system resources. Another advantage is that relatively complex relationships can be captured without having to transform the feature space or doing much hyperparameter tuning. We can demonstrate this with the NBA data we worked with in the previous chapter.

We will work with data on National Basketball Association (NBA) games in this section. The dataset contains statistics from each NBA game from the 2017/2018 season through the 2020/2021 season. This includes the home team; whether the home team won; the visiting team; shooting percentages for visiting and home teams; turnovers, rebounds, and assists by both teams; and several other measures.

Note

The NBA game data can be downloaded by the public at https://www.kaggle.com/datasets/wyattowalsh/basketball. This dataset...