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

Hyperparameter Tuning with GridSearchCV

GridSearchCV will take a model and parameters and train one model for each permutation of the parameters. At the end of the training, it will provide access to the parameters and the model scores. This is called hyperparameter tuning and you will be looking at this in much more depth in Chapter 8, Hyperparameter Tuning.

The usual practice is to make use of a small training set to find the optimal parameters using hyperparameter tuning and then to train a final model with all of the data.

Before the next exercise, let's take a brief look at decision trees, which are a type of model or estimator.

Decision Trees

A decision tree works by generating a separating hyperplane or a threshold for the features in data. It does this by considering every feature and finding the correlation between the spread of the values in that feature and the label that you are trying to predict.

Consider the following data about balloons. The...