Book Image

Designing Machine Learning Systems with Python

By : David Julian
Book Image

Designing Machine Learning Systems with Python

By: David Julian

Overview of this book

Machine learning is one of the fastest growing trends in modern computing. It has applications in a wide range of fields, including economics, the natural sciences, web development, and business modeling. In order to harness the power of these systems, it is essential that the practitioner develops a solid understanding of the underlying design principles. There are many reasons why machine learning models may not give accurate results. By looking at these systems from a design perspective, we gain a deeper understanding of the underlying algorithms and the optimisational methods that are available. This book will give you a solid foundation in the machine learning design process, and enable you to build customised machine learning models to solve unique problems. You may already know about, or have worked with, some of the off-the-shelf machine learning models for solving common problems such as spam detection or movie classification, but to begin solving more complex problems, it is important to adapt these models to your own specific needs. This book will give you this understanding and more.
Table of Contents (16 chapters)
Designing Machine Learning Systems with Python
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Free Chapter
1
Thinking in Machine Learning
Index

Learning curves


An important way to understand how a model is performing is by using learning curves. Consider what happens to the training and test errors as we increase the number of samples. Consider a simple linear model. With few training samples, it is very easy for it to fit the parameters, the training error will be small. As the training set grows, it becomes harder to fit, and the average training error will likely grow. On the other hand, the cross validation error will likely decrease, at least at the beginning, as samples are added. With more samples to train on, the model will be better able to acclimatize to new samples. Consider a model with high bias, for example, a simple linear classifier with two parameters. This is just a straight line, so as we start adding training examples, the cross validation error will initially decrease. However, after a certain point, adding training examples will not reduce the error significantly simply because of the limitations of a straight...