Lissajous Curves

The curves are defined by these equations:
c(t) = RR*[ sin(xfrequ*t), cos(yfrequ*t), sin(zfrequ*t)/4 ]
The curve shows the movement of an oscillator with different frequencies in x-, y- and z-direction.
The default frequencies show knots with alternating under/over. Such alternating knots cannot be drawn with fewer crossings.