I was wondering if there is an easy way to add multi-level/hierarchical/grouping of axis label in d3. For example, if I have a line chart with month name for x-axis spanning across multiple years, I would want to also have year as label below the month names so it looks something like this.
Oct Nov Dec Jan Feb Mar Apr
|_____________| |___________________|
2011 2012
I understand that you can do anything in SVG to make it works, but I want to use d3 as much as possible so that it's much easier to update the chart dynamically.
Thanks, Jack