Book Image

The Supervised Learning Workshop - Second Edition

By : Blaine Bateman, Ashish Ranjan Jha, Benjamin Johnston, Ishita Mathur
Book Image

The Supervised Learning Workshop - Second Edition

By: Blaine Bateman, Ashish Ranjan Jha, Benjamin Johnston, Ishita Mathur

Overview of this book

Would you like to understand how and why machine learning techniques and data analytics are spearheading enterprises globally? From analyzing bioinformatics to predicting climate change, machine learning plays an increasingly pivotal role in our society. Although the real-world applications may seem complex, this book simplifies supervised learning for beginners with a step-by-step interactive approach. Working with real-time datasets, you’ll learn how supervised learning, when used with Python, can produce efficient predictive models. Starting with the fundamentals of supervised learning, you’ll quickly move to understand how to automate manual tasks and the process of assessing date using Jupyter and Python libraries like pandas. Next, you’ll use data exploration and visualization techniques to develop powerful supervised learning models, before understanding how to distinguish variables and represent their relationships using scatter plots, heatmaps, and box plots. After using regression and classification models on real-time datasets to predict future outcomes, you’ll grasp advanced ensemble techniques such as boosting and random forests. Finally, you’ll learn the importance of model evaluation in supervised learning and study metrics to evaluate regression and classification tasks. By the end of this book, you’ll have the skills you need to work on your real-life supervised learning Python projects.
Table of Contents (9 chapters)

Ordinary Least Squares as a Classifier

We covered ordinary least squares (OLS) as linear regression in the context of predicting continuous variable output in the previous chapter, but it can also be used to predict the class that a set of data is a member of. OLS-based classifiers are not as powerful as other types of classifiers that we will cover in this chapter, but they are particularly useful in understanding the process of classification. To recap, an OLS-based classifier is a non-probabilistic, linear binary classifier. It is non-probabilistic because it does not generate any confidence over the prediction such as, for example, logistic regression. It is a linear classifier as it has a linear relationship with respect to its parameters/coefficient.

Now, let's say we had a fictional dataset containing two separate groups, Xs and Os, as shown in Figure 5.1. We could construct a linear classifier by first using OLS linear regression to fit the equation of a straight line...