Book Image

The Data Science Workshop

By : Anthony So, Thomas V. Joseph, Robert Thas John, Andrew Worsley, Dr. Samuel Asare
Book Image

The Data Science Workshop

By: Anthony So, Thomas V. Joseph, Robert Thas John, Andrew Worsley, Dr. Samuel Asare

Overview of this book

You already know you want to learn data science, and a smarter way to learn data science is to learn by doing. The Data Science Workshop focuses on building up your practical skills so that you can understand how to develop simple machine learning models in Python or even build an advanced model for detecting potential bank frauds with effective modern data science. You'll learn from real examples that lead to real results. Throughout The Data Science Workshop, you'll take an engaging step-by-step approach to understanding data science. You won't have to sit through any unnecessary theory. If you're short on time you can jump into a single exercise each day or spend an entire weekend training a model using sci-kit learn. It's your choice. Learning on your terms, you'll build up and reinforce key skills in a way that feels rewarding. Every physical print copy of The Data Science Workshop unlocks access to the interactive edition. With videos detailing all exercises and activities, you'll always have a guided solution. You can also benchmark yourself against assessments, track progress, and receive content updates. You'll even earn a secure credential that you can share and verify online upon completion. It's a premium learning experience that's included with your printed copy. To redeem, follow the instructions located at the start of your data science book. Fast-paced and direct, The Data Science Workshop is the ideal companion for data science beginners. You'll learn about machine learning algorithms like a data scientist, learning along the way. This process means that you'll find that your new skills stick, embedded as best practice. A solid foundation for the years ahead.
Table of Contents (18 chapters)

Choosing the Number of Clusters

In the previous sections, we saw how easy it is to fit the k-means algorithm on a given dataset. In our ATO dataset, we found 8 different clusters that were mainly defined by the values of the Average net tax variable.

But you may have asked yourself: "Why 8 clusters? Why not 3 or 15 clusters?" These are indeed excellent questions. The short answer is that we used k-means' default value for the hyperparameter n_cluster, defining the number of clusters to be found, as 8.

As you will recall from Chapter 2, Regression, and Chapter 4, Multiclass Classification (NLP), the value of a hyperparameter isn't learned by the algorithm but has to be set arbitrarily by you prior to training. For k-means, n_cluster is one of the most important hyperparameters you will have to tune. Choosing a low value will lead k-means to group many data points together, even though they are very different from each other. On the other hand, choosing a high...