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

Linear Model Coefficients

In Chapter 2, Regression, and Chapter 3, Binary Classification, you saw that linear regression models learn function parameters in the form of the following:

Figure 9.1: Function parameters for linear regression models

The objective is to find the best parameters (w1, w2 …, wn) that will get the predictions, ŷ̂, very close to the actual target values, y. So, once you have trained your model and are getting good predictive performance without much overfitting, you can use these parameters (or coefficients) to understand which variables largely impacted the predictions. If a coefficient is close to 0, this means the related feature didn't impact much the outcome. On the other hand, if it is quite high (positively or negatively), it means its feature is influencing the prediction outcome vastly.

Let's take the example of the following function: 100 + 0.2 * x1 + 200 * x2 - 180 * x3. The coefficient of...