Functions for a generalised Lissajous Pendulum

Maybe you're already familiar with Lissajous figures. These can be realised by any oscilloscope or even with refined mechanical pendulums (harmonographs), cf. woodgears.ca or karlsims.com, whereby of course potential energy is lost: the pendulum comes to a standstill. Here you can imitate this by adjusting the sliders manually or via your forward and backward keys. Have fun!