- Author:
- David Nickerson <david.nickerson@gmail.com>
- Date:
- 2021-09-17 15:50:49+12:00
- Desc:
- tweak html formatting
- Permanent Source URI:
- https://models.fieldml.org/workspace/a1/rawfile/1b3862589abf79ae9119ee0b5e99a8b785d762e1/dojo-presentation/js/dojo/dojox/math/_base.js
dojo.provide("dojox.math._base");
dojo.mixin(dojox.math, {
degreesToRadians: function(/* Number */n){
// summary
// Convert the passed number to radians.
return (n*Math.PI)/180; // Number
},
radiansToDegrees: function(/* Number */n){
// summary
// Convert the passed number to degrees.
return (n*180)/Math.PI; // Number
},
factorial: function(/* Number */n){
// summary
// Return the factorial of n
if(n === 0){
return 1; // Number
}else if(n < 0 || Math.floor(n) != n){
return NaN; // NaN
}
var ret = 1;
for(var i = 1; i <= n; i++){
ret *= i;
}
return ret; // Number
},
permutations: function(/* Number */n, /* Number */k){
// summary
// TODO
if(n==0 || k==0){
return 1; // Number
}
return this.factorial(n) / this.factorial(n-k);
},
combinations: function(/* Number */n, /* Number */r){
// summary
// TODO
if(n==0 || r==0){
return 1; // Number
}
return this.factorial(n) / (this.factorial(n-r) * this.factorial(r)); // Number
},
bernstein: function(/* Number */t, /* Number */n, /* Number */ i){
// summary
// TODO
return this.combinations(n, i) * Math.pow(t, i) * Math.pow(1-t, n-i); // Number
},
gaussian: function(){
// summary
// Return a random number based on the Gaussian algo.
var k=2;
do{
var i=2*Math.random()-1;
var j=2*Math.random()-1;
k = i*i+j*j;
}while(k>=1);
return i * Math.sqrt((-2*Math.log(k))/k); // Number
},
// basic statistics
sd: function(/* Array */a){
// summary
// Returns the standard deviation of the passed arguments.
return Math.sqrt(this.variance(a)); // Number
},
variance: function(/* Array */a){
// summary
// Find the variance in the passed array of numbers.
var mean=0, squares=0;
dojo.forEach(a, function(item){
mean+=item;
squares+=Math.pow(item,2);
});
return (squares/a.length)-Math.pow(mean/a.length, 2); // Number
},
// create a range of numbers
range: function(/* Number */a, /* Number? */b, /* Number? */step){
// summary
// Create a range of numbers based on the parameters.
if(arguments.length<2){
b=a,a=0;
}
var range=[], s=step||1, i;
if(s>0){
for(i=a; i<b; i+=s){
range.push(i);
}
}else{
if(s<0){
for(i=a; i>b; i+=s){
range.push(i);
}
}else{
throw new Error("dojox.math.range: step must not be zero.");
}
}
return range; // Array
},
distance: function(/* Array */a, /* Array */b){
// summary
// Calculate the distance between point A and point B
return Math.sqrt(Math.pow(b[0]-a[0],2)+Math.pow(b[1]-a[1],2)); // Number
},
midpoint: function(/* Array */a, /* Array */b){
// summary
// Calculate the midpoint between points A and B. A and B may be multidimensional.
if(a.length!=b.length){
console.error("dojox.math.midpoint: Points A and B are not the same dimensionally.", a, b);
}
var m=[];
for(var i=0; i<a.length; i++){
m[i]=(a[i]+b[i])/2;
}
return m; // Array
}
});