%CO:A,12,72%%H2%PLOTFX.BAS%H2% again runs under the Basic patch and is a general function
plotter, with a fixed origin at the centre of the screen. Functions
should be entered in standard computer maths syntax, in terms of X;
that is, for instance, to get a plot of "five times X squared plus 3
times X plus 10" you should enter 2*X^2+3*X+10.