http://www.bulgarienhus.ru/js/jquery.easing.js

1/*
2 * jQuery Easing v1.1.1 - http://gsgd.co.uk/sandbox/jquery.easing.php
3 *
4 * Uses the built in easing capabilities added in jQuery 1.1
5 * to offer multiple easing options
6 *
7 * Copyright (c) 2007 George Smith
8 * Licensed under the MIT License:
9 *   http://www.opensource.org/licenses/mit-license.php
10 */
11
12jQuery.extend({
13	easing: {
14		easein: function(x, t, b, c, d) {
15			return c*(t/=d)*t + b; // in
16		},
17		easeinout: function(x, t, b, c, d) {
18			if (t < d/2) return 2*c*t*t/(d*d) + b;
19			var ts = t - d/2;
20			return -2*c*ts*ts/(d*d) + 2*c*ts/d + c/2 + b;		
21		},
22		easeout: function(x, t, b, c, d) {
23			return -c*t*t/(d*d) + 2*c*t/d + b;
24		},
25		expoin: function(x, t, b, c, d) {
26			var flip = 1;
27			if (c < 0) {
28				flip *= -1;
29				c *= -1;
30			}
31			return flip * (Math.exp(Math.log(c)/d * t)) + b;		
32		},
33		expoout: function(x, t, b, c, d) {
34			var flip = 1;
35			if (c < 0) {
36				flip *= -1;
37				c *= -1;
38			}
39			return flip * (-Math.exp(-Math.log(c)/d * (t-d)) + c + 1) + b;
40		},
41		expoinout: function(x, t, b, c, d) {
42			var flip = 1;
43			if (c < 0) {
44				flip *= -1;
45				c *= -1;
46			}
47			if (t < d/2) return flip * (Math.exp(Math.log(c/2)/(d/2) * t)) + b;
48			return flip * (-Math.exp(-2*Math.log(c/2)/d * (t-d)) + c + 1) + b;
49		},
50		bouncein: function(x, t, b, c, d) {
51			return c - jQuery.easing['bounceout'](x, d-t, 0, c, d) + b;
52		},
53		bounceout: function(x, t, b, c, d) {
54			if ((t/=d) < (1/2.75)) {
55				return c*(7.5625*t*t) + b;
56			} else if (t < (2/2.75)) {
57				return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b;
58			} else if (t < (2.5/2.75)) {
59				return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b;
60			} else {
61				return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b;
62			}
63		},
64		bounceinout: function(x, t, b, c, d) {
65			if (t < d/2) return jQuery.easing['bouncein'] (x, t*2, 0, c, d) * .5 + b;
66			return jQuery.easing['bounceout'] (x, t*2-d,0, c, d) * .5 + c*.5 + b;
67		},
68		elasin: function(x, t, b, c, d) {
69			var s=1.70158;var p=0;var a=c;
70			if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*.3;
71			if (a < Math.abs(c)) { a=c; var s=p/4; }
72			else var s = p/(2*Math.PI) * Math.asin (c/a);
73			return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
74		},
75		elasout: function(x, t, b, c, d) {
76			var s=1.70158;var p=0;var a=c;
77			if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*.3;
78			if (a < Math.abs(c)) { a=c; var s=p/4; }
79			else var s = p/(2*Math.PI) * Math.asin (c/a);
80			return a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b;
81		},
82		elasinout: function(x, t, b, c, d) {
83			var s=1.70158;var p=0;var a=c;
84			if (t==0) return b;  if ((t/=d/2)==2) return b+c;  if (!p) p=d*(.3*1.5);
85			if (a < Math.abs(c)) { a=c; var s=p/4; }
86			else var s = p/(2*Math.PI) * Math.asin (c/a);
87			if (t < 1) return -.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
88			return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*.5 + c + b;
89		},
90		backin: function(x, t, b, c, d) {
91			var s=1.70158;
92			return c*(t/=d)*t*((s+1)*t - s) + b;
93		},
94		backout: function(x, t, b, c, d) {
95			var s=1.70158;
96			return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
97		},
98		backinout: function(x, t, b, c, d) {
99			var s=1.70158;
100			if ((t/=d/2) < 1) return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b;
101			return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b;
102		},
103		linear: function(x, t, b, c, d) {
104			return c*t/d + b; //linear
105		}
106	}
107});