Core Animation Object - Pull Back

Animation pulls back and 'launches' a variable. This example shows the radius of a circle reducing by a set amount then icreasing to a set value, plus draws the output curve.
Animation Settings:
1. Smoothness50 frames per second
2. Duration2000 - runtime in ms
3. Range 130 increase in circle radius
4. Set Pull BackR = 3 pull back ratio
5. Output Equationfunction back(p, x){x=R;return Math.pow(p, 2) * ((x + 1) * p - x)}
6. Application Output myCircle.r.baseVal.value
Pull Back:

SVG Source:
OK in:IE11/CH32/FF23