I want to show the effect of threshold on FAR and FRR( basically the region under a curve with when the x-range is bounded ). To do that I need to do something like this!! image
If the threshold is changed so does the values. I have to illustrate similar concepts and so have to draw a lot of similar curves and do some basic effects( using colour ) on the curve. Now this is not exactly a mathematical function. Also it is not much useful to plot these values after gathering data. Is there some graphic tool( possibly free ) that I can use to draw this type of general graphs. Is there a way or do I need to write code( python matplot/octave ) to do this?