Robert Penner's easing functions as Observables.
// All easing functions take a begin value, end value, and duration (in ms).
// A few take extra arguments, which I've documented
Observable.backIn = function(begin, end, duration, overshoot) {};
Observable.backOut = function(begin, end, duration, overshoot) {};
Observable.backInOut = function(begin, end, duration, overshoot) {};
Observable.bounceIn = function(begin, end, duration) {};
Observable.bounceOut = function(begin, end, duration) {};
Observable.bounceInOut = function(begin, end, duration) {};
Observable.circIn = function(begin, end, duration) {};
Observable.circOut = function(begin, end, duration) {};
Observable.circInOut = function(begin, end, duration) {};
Observable.cubicIn = function(begin, end, duration) {};
Observable.cubicOut = function(begin, end, duration) {};
Observable.cubicInOut = function(begin, end, duration) {};
Observable.elasticOut = function(begin, end, duration, amplitude, period) {};
Observable.elasticIn = function(begin, end, duration, amplitude, period) {};
Observable.elasticInOut = function(begin, end, duration, amplitude, period) {};
Observable.expoIn = function(begin, end, duration) {};
Observable.expoOut = function(begin, end, duration) {};
Observable.expoInOut = function(begin, end, duration) {};
Observable.linear = function(begin, end, duration) {};
Observable.quadIn = function(begin, end, duration) {};
Observable.quadOut = function(begin, end, duration) {};
Observable.quadInOut = function(begin, end, duration) {};
Observable.quartIn = function(begin, end, duration) {};
Observable.quartOut = function(begin, end, duration) {};
Observable.quartInOut = function(begin, end, duration) {};
Observable.quintIn = function(begin, end, duration) {};
Observable.quintOut = function(begin, end, duration) {};
Observable.quintInOut = function(begin, end, duration) {};
Observable.sineIn = function(begin, end, duration) {};
Observable.sineOut = function(begin, end, duration) {};
Observable.sineInOut = function(begin, end, duration) {};
Observable.circleIn = function(begin, end, duration) {};
Observable.circleOut = function(begin, end, duration) {};
Observable.circleInOut = function(begin, end, duration) {};
Observable.linearNone = function(begin, end, duration) {};
Observable.linearIn = function(begin, end, duration) {};
Observable.linearOut = function(begin, end, duration) {};
Observable.linearInOut = function(begin, end, duration) {};
