Machine Learning Systems

Chapter 4. Generating features

This chapter covers

• Extracting features from raw data
• Transforming features to make them more useful
• Selecting among the features you’ve created
• How to organize feature-generation code

This chapter is the next step on our journey through the components, or phases, of a machine learning system, shown in figure 4.1. The chapter focuses on turning raw data into useful representations called features. The process of building systems that can generate features from data, sometimes called feature engineering, can be deceptively complex. Often, people begin with an intuitive understanding of what they want the features used in a system to be, with few plans for how those features will be produced. Without a solid plan, ...