Book Image

The Data Science Workshop - Second Edition

By : Anthony So, Thomas V. Joseph, Robert Thas John, Andrew Worsley, Dr. Samuel Asare
5 (1)
Book Image

The Data Science Workshop - Second Edition

5 (1)
By: Anthony So, Thomas V. Joseph, Robert Thas John, Andrew Worsley, Dr. Samuel Asare

Overview of this book

Where there’s data, there’s insight. With so much data being generated, there is immense scope to extract meaningful information that’ll boost business productivity and profitability. By learning to convert raw data into game-changing insights, you’ll open new career paths and opportunities. The Data Science Workshop begins by introducing different types of projects and showing you how to incorporate machine learning algorithms in them. You’ll learn to select a relevant metric and even assess the performance of your model. To tune the hyperparameters of an algorithm and improve its accuracy, you’ll get hands-on with approaches such as grid search and random search. Next, you’ll learn dimensionality reduction techniques to easily handle many variables at once, before exploring how to use model ensembling techniques and create new features to enhance model performance. In a bid to help you automatically create new features that improve your model, the book demonstrates how to use the automated feature engineering tool. You’ll also understand how to use the orchestration and scheduling workflow to deploy machine learning models in batch. By the end of this book, you’ll have the skills to start working on data science projects confidently. By the end of this book, you’ll have the skills to start working on data science projects confidently.
Table of Contents (16 chapters)
Preface
12
12. Feature Engineering

Calculating the Distance to the Centroid

We've talked a lot about similarities between data points in the previous sections, but we haven't really defined what this means. You have probably guessed that it has something to do with how close or how far observations are from each other. You are heading in the right direction. It has to do with some sort of distance measure between two points. The one used by k-means is called squared Euclidean distance and its formula is:

Figure 5.32: The squared Euclidean distance formula

If you don't have a statistical background, this formula may look intimidating, but it is actually very simple. It is the sum of the squared difference between the data coordinates. Here, x and y are two data points and the index, i, represents the number of coordinates. If the data has two dimensions, i equals 2. Similarly, if there are three dimensions, then i will be 3.

Let's apply this formula to the ATO dataset....