I always understood it to be that the "typographic resolution" aspect of sparklines was an important characteristic and that you really couldn't display a proper sparkline on a screen because most screens just don't have the resolution of printed material. The idea was that the human eye could glean useful information from charts with 600 or even 1200 data points per inch and so you could pack an incredible amount of data into a small space. Even retina displays are only about half that, though most "sparklines" I see don't even attempt that density.
Does anyone know if sparklines are actually used that way? The only place I've seen really dense sparklines are Tufte's books. Most I've seen in the wild seem to have just a handful of data points.
Does anyone know if sparklines are actually used that way? The only place I've seen really dense sparklines are Tufte's books. Most I've seen in the wild seem to have just a handful of data points.