Square Wave Function

How do I use math functions within TorqueScript?

Say I have my basic script:

function FishClass::onLevelLoaded(%this, %scenegraph)
{
%this.setLinearVelocityX(20);
}


And say I wanted to make my FishClass move in a really jagged way, like an old Game and Watch handheld. Like this:

www.youtube.com/watch?v=HfKoEWN65Qo


I want to use a function would be a square wave. Like this:



So how does a person do that? Hell, even if it was a simple sine function, how would I plug it in?