Sparklines with the Google Chart API
Sparklines are described in Edward Tufte's book Beautiful Evidence (2006) as “small, high resolution graphics embedded in a context of words, numbers, images”. In one of our projects we needed sparklines and one option was to use this open source package by Larry Ogrodnek. Just out of curiousity I was wondering how far we would come if we would use the Google Chart API.
That was until I ran into this article where I saw sparklines created with the Google Charts API and without the x- and y-axis. How the hell did he do it?
Well ... it seems to be an undocumented feature also used by Google on their financial site. Instead of using cht=lc (chartype is line chart) you can use cht=lfi (charttype is financial line chart).