This interactive web page, programmed by using JavaScript to draw on an HTML5 canvas object, shows the effect of changing the parameters of the functions that define a harmonograph figure, which is a Lissajous curve with damping applied to the periodic functions which define it.

x(t)=e^(-t)*cos(t+)

y(t)=e^(-t)*cos(t+)

domain: t is in [0, *pi]