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)

Logistic Regression

The logistic, or logit, model is a linear model that has been effectively used for classification tasks in a number of different domains. Recalling the definition of the OLS model from the previous section, the logistic regression model takes as input a linear combination of the input features. In this section, we will use it to classify images of handwritten digits. In understanding the logistic model, we also take an important step in understanding the operation of a particularly powerful machine learning model – artificial neural networks. So, what exactly is the logistic model? Like the OLS model, which is composed of a linear or straight-line function, the logistic model is composed of the standard logistic function, which, in mathematical terms, looks something like this:

Figure 5.7: Logistic function

In practical terms, when trained, this function returns the probability of the input information belonging to a particular class...