Field Guide to Rendering Charts

2020-01-23

There are four foundations upon which this package rests:

• the Altair Python package, to build chart specifications
• the reticulate R package, to provide inter-operability with Python
• the Vega-Lite JavaScript framework, to render chart specifications in an HTML file
• the vegawidget R package, which relies on htmlwidgets to provide inter-operability with HTML and JavaScript

This article deals with the second two items; the Field Guide to Python Issues deals with the first two.

Vegawidget

All the rendering is handled by vegawidget; so you are referred to its article on rendering.

The two main issues on rendering are:

• sizing
• arguments passed to vega-embed (more specialized)

These are discussed in these sections of the vegawidget rendering-article:

• Using vegawidget arguments, calling the vegawidget() function
• Setting R options, can be set a number of ways
• Knitting strategies, including how to render Vega(-Lite) charts when knitting to a non-HTML format such as PDF.