Created attachment 71145 [details]
Example highlighted period

It would be nice if there was an option to fill the area under a curve (from the curve line back towards zero), or between a minimum and maximum (for example, fill between the error bars).

One example of a use for this is for displaying signal envelopes.

It could also be used to highlight areas of a plot along the X axis (a curve with a square wave and fill could be used as the rearmost curve in order to colour the background of more frontal line only curves). As an example see attached "highlight_time_periods.png".

It could also be used to show category vs time (horizontal bars through time for different categories or states, like a horizontal UML sequence diagram, which is sometimes used in system pofiling, e.g. http://www.qnx.com/developers/docs/6.3.0SP3/ide_en/user_guide/sysprof.html). As an example, see attached "sequence.png".

I realise I can kind of achieve the same effect with barcharts but barcharts have defined bars with edges whereas this would just be a floodfill. Barcharts are also pretty slow when you have thousands of data samples.