Skip to Main Content
Hands-On Machine Learning with Scikit-Learn, Keras, and TensorFlow, 2nd Edition
book

Hands-On Machine Learning with Scikit-Learn, Keras, and TensorFlow, 2nd Edition

by Aurélien Géron
September 2019
Intermediate to advanced content levelIntermediate to advanced
848 pages
24h 18m
English
O'Reilly Media, Inc.
Content preview from Hands-On Machine Learning with Scikit-Learn, Keras, and TensorFlow, 2nd Edition

Chapter 3. Classification

In Chapter 1 I mentioned that the most common supervised learning tasks are regression (predicting values) and classification (predicting classes). In Chapter 2 we explored a regression task, predicting housing values, using various algorithms such as Linear Regression, Decision Trees, and Random Forests (which will be explained in further detail in later chapters). Now we will turn our attention to classification systems.

MNIST

In this chapter we will be using the MNIST dataset, which is a set of 70,000 small images of digits handwritten by high school students and employees of the US Census Bureau. Each image is labeled with the digit it represents. This set has been studied so much that it is often called the “hello world” of Machine Learning: whenever people come up with a new classification algorithm they are curious to see how it will perform on MNIST, and anyone who learns Machine Learning tackles this dataset sooner or later.

Scikit-Learn provides many helper functions to download popular datasets. MNIST is one of them. The following code fetches the MNIST dataset:1

>>> from sklearn.datasets import fetch_openml
>>> mnist = fetch_openml('mnist_784', version=1)
>>> mnist.keys()
dict_keys(['data', 'target', 'feature_names', 'DESCR', 'details',
           'categories', 'url'])

Datasets loaded by Scikit-Learn generally have a similar dictionary structure, including the following:

  • A DESCR key describing the dataset

  • A data key containing an array with one ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Hands-On Machine Learning with Scikit-Learn, Keras, and TensorFlow, 3rd Edition

Hands-On Machine Learning with Scikit-Learn, Keras, and TensorFlow, 3rd Edition

Aurélien Géron
Machine Learning with PyTorch and Scikit-Learn

Machine Learning with PyTorch and Scikit-Learn

Sebastian Raschka, Yuxi (Hayden) Liu, Vahid Mirjalili

Publisher Resources

ISBN: 9781492032632Errata Page