Hi,

Could be nice to implement a feature which put some extra info in the tooltip, like a date info for time series or other info coming by another vector with the same length of the current tooltip data.

I found some discussion about it about the original sparkline jquery:
gwatts/jquery.sparkline#111
https://groups.google.com/forum/?fromgroups#!topic/jquery-sparkline/WJMFn87yWq0
https://groups.google.com/forum/#!msg/jquery-sparkline/0rtcTRAuT-A/SIF_exL0tDsJ

Thanks!