128 lines
2.9 KiB
JavaScript
128 lines
2.9 KiB
JavaScript
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dojo.provide("dojox.math._base");
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dojo.mixin(dojox.math, {
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degreesToRadians: function(/* Number */n){
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// summary
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// Convert the passed number to radians.
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return (n*Math.PI)/180; // Number
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},
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radiansToDegrees: function(/* Number */n){
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// summary
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// Convert the passed number to degrees.
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return (n*180)/Math.PI; // Number
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},
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factorial: function(/* Number */n){
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// summary
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// Return the factorial of n
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if(n === 0){
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return 1; // Number
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}else if(n < 0 || Math.floor(n) != n){
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return NaN; // NaN
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}
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var ret = 1;
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for(var i = 1; i <= n; i++){
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ret *= i;
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}
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return ret; // Number
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},
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permutations: function(/* Number */n, /* Number */k){
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// summary
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// TODO
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if(n==0 || k==0){
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return 1; // Number
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}
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return this.factorial(n) / this.factorial(n-k);
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},
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combinations: function(/* Number */n, /* Number */r){
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// summary
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// TODO
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if(n==0 || r==0){
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return 1; // Number
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}
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return this.factorial(n) / (this.factorial(n-r) * this.factorial(r)); // Number
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},
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bernstein: function(/* Number */t, /* Number */n, /* Number */ i){
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// summary
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// TODO
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return this.combinations(n, i) * Math.pow(t, i) * Math.pow(1-t, n-i); // Number
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},
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gaussian: function(){
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// summary
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// Return a random number based on the Gaussian algo.
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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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return i * Math.sqrt((-2*Math.log(k))/k); // Number
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},
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// basic statistics
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sd: function(/* Array */a){
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// summary
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// Returns the standard deviation of the passed arguments.
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return Math.sqrt(this.variance(a)); // Number
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},
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variance: function(/* Array */a){
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// summary
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// Find the variance in the passed array of numbers.
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var mean=0, squares=0;
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dojo.forEach(a, function(item){
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mean+=item;
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squares+=Math.pow(item,2);
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});
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return (squares/a.length)-Math.pow(mean/a.length, 2); // Number
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},
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// create a range of numbers
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range: function(/* Number */a, /* Number? */b, /* Number? */step){
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// summary
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// Create a range of numbers based on the parameters.
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if(arguments.length<2){
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b=a,a=0;
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}
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var range=[], s=step||1, i;
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if(s>0){
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for(i=a; i<b; i+=s){
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range.push(i);
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}
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}else{
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if(s<0){
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for(i=a; i>b; i+=s){
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range.push(i);
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}
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}else{
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throw new Error("dojox.math.range: step must not be zero.");
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}
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}
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return range; // Array
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},
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distance: function(/* Array */a, /* Array */b){
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// summary
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// Calculate the distance between point A and point B
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return Math.sqrt(Math.pow(b[0]-a[0],2)+Math.pow(b[1]-a[1],2)); // Number
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},
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midpoint: function(/* Array */a, /* Array */b){
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// summary
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// Calculate the midpoint between points A and B. A and B may be multidimensional.
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if(a.length!=b.length){
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console.error("dojox.math.midpoint: Points A and B are not the same dimensionally.", a, b);
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}
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var m=[];
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for(var i=0; i<a.length; i++){
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m[i]=(a[i]+b[i])/2;
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}
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return m; // Array
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}
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});
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