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1318 alexandre_ 1 
/*
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	Copyright (c) 2004-2006, The Dojo Foundation
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	All Rights Reserved.
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	Licensed under the Academic Free License version 2.1 or above OR the
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	modified BSD license. For more information on Dojo licensing, see:
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		http://dojotoolkit.org/community/licensing.shtml
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*/
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dojo.provide("dojo.math");
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dojo.math.degToRad = function (x) {
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	return (x * Math.PI) / 180;
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};
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dojo.math.radToDeg = function (x) {
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	return (x * 180) / Math.PI;
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};
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dojo.math.factorial = function (n) {
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	if (n < 1) {
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		return 0;
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	}
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	var retVal = 1;
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	for (var i = 1; i <= n; i++) {
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		retVal *= i;
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	}
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	return retVal;
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};
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dojo.math.permutations = function (n, k) {
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	if (n == 0 || k == 0) {
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		return 1;
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	}
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	return (dojo.math.factorial(n) / dojo.math.factorial(n - k));
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};
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dojo.math.combinations = function (n, r) {
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	if (n == 0 || r == 0) {
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		return 1;
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	}
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	return (dojo.math.factorial(n) / (dojo.math.factorial(n - r) * dojo.math.factorial(r)));
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};
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dojo.math.bernstein = function (t, n, i) {
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	return (dojo.math.combinations(n, i) * Math.pow(t, i) * Math.pow(1 - t, n - i));
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};
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dojo.math.gaussianRandom = function () {
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	var k = 2;
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	do {
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		var i = 2 * Math.random() - 1;
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		var j = 2 * Math.random() - 1;
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		k = i * i + j * j;
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	} while (k >= 1);
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	k = Math.sqrt((-2 * Math.log(k)) / k);
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	return i * k;
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};
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dojo.math.mean = function () {
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	var array = dojo.lang.isArray(arguments[0]) ? arguments[0] : arguments;
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	var mean = 0;
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	for (var i = 0; i < array.length; i++) {
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		mean += array[i];
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	}
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	return mean / array.length;
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};
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dojo.math.round = function (number, places) {
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	if (!places) {
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		var shift = 1;
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	} else {
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		var shift = Math.pow(10, places);
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	}
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	return Math.round(number * shift) / shift;
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};
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dojo.math.sd = dojo.math.standardDeviation = function () {
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	var array = dojo.lang.isArray(arguments[0]) ? arguments[0] : arguments;
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	return Math.sqrt(dojo.math.variance(array));
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};
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dojo.math.variance = function () {
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	var array = dojo.lang.isArray(arguments[0]) ? arguments[0] : arguments;
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	var mean = 0, squares = 0;
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	for (var i = 0; i < array.length; i++) {
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		mean += array[i];
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		squares += Math.pow(array[i], 2);
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	}
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	return (squares / array.length) - Math.pow(mean / array.length, 2);
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};
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dojo.math.range = function (a, b, step) {
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	if (arguments.length < 2) {
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		b = a;
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		a = 0;
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	}
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	if (arguments.length < 3) {
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		step = 1;
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	}
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	var range = [];
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	if (step > 0) {
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		for (var i = a; i < b; i += step) {
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			range.push(i);
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		}
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	} else {
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		if (step < 0) {
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			for (var i = a; i > b; i += step) {
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				range.push(i);
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			}
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		} else {
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			throw new Error("dojo.math.range: step must be non-zero");
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		}
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	}
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	return range;
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};
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