Data Visualization with Python and JavaScript

Chapter 10. Visualizing Data with Matplotlib

As a data visualizer, one of the best ways to come to grips with your data is to visualize it interactively, using the full range of charts and plots that have evolved to summarize and refine datasets. Conventionally, the fruits of this exploratory phase are then presented as static figures, but increasingly they are used to construct more engaging interactive web-based charts, such as the cool D3 visualizations you have probably seen (one of which we’ll be building in Part V).

Python’s Matplotlib and its family of extensions (such as the statistically focused Seaborn) form a mature and very customizable plotting ecosystem. Matplotlib plots can be used interactively by IPython (the Qt and Notebook versions), providing a very powerful and intuitive way of finding interesting nuggets in your data. In this chapter we’ll introduce Matplotlib and one of its great extensions, Seaborn.

Pyplot and Object-Oriented Matplotlib

Matplotlib can be more than a little confusing, especially if you start randomly sampling examples online. The main complicating factor is that there are two main ways to create plots, which are similar enough to be confused but different enough to lead to a lot of frustrating errors. The first way uses a global state machine to interact directly with Matplotlib’s pyplot module. The second, object-oriented approach uses the more familiar notion of figure and axes classes to provide a programmatic alternative. I’ll clarify ...