This is a fork of mbostock's grouped bar chart example, to demonstrate how to use crossfilter to produce the same result.
This grouped bar chart is constructed from a CSV file storing the populations of different states by age group. The chart employs conventional margins and a number of D3 features:
https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js
https://cdnjs.cloudflare.com/ajax/libs/crossfilter/1.3.12/crossfilter.min.js