54 lines
1.1 KiB
JavaScript
54 lines
1.1 KiB
JavaScript
|
/**
|
||
|
|
* @license Fraction.js v2.7.0 01/06/2015
|
||
|
|
* http://www.xarg.org/2014/03/rational-numbers-in-javascript/
|
||
|
|
*
|
||
|
|
* Copyright (c) 2015, Robert Eisele (robert@xarg.org)
|
||
|
|
* Dual licensed under the MIT or GPL Version 2 licenses.
|
||
|
|
**/
|
||
|
|
|
||
|
|
// Another rational approximation, not using Farey Sequences but Binary Search using the mediant
|
||
|
|
function approximate(p, precision) {
|
||
|
|
|
||
|
|
var num1 = Math.floor(p);
|
||
|
|
var den1 = 1;
|
||
|
|
|
||
|
|
var num2 = num1 + 1;
|
||
|
|
var den2 = 1;
|
||
|
|
|
||
|
|
if (p !== num1) {
|
||
|
|
|
||
|
|
while (den1 <= precision && den2 <= precision) {
|
||
|
|
|
||
|
|
var m = (num1 + num2) / (den1 + den2);
|
||
|
|
|
||
|
|
if (p === m) {
|
||
|
|
|
||
|
|
if (den1 + den2 <= precision) {
|
||
|
|
den1 += den2;
|
||
|
|
num1 += num2;
|
||
|
|
den2 = precision + 1;
|
||
|
|
} else if (den1 > den2) {
|
||
|
|
den2 = precision + 1;
|
||
|
|
} else {
|
||
|
|
den1 = precision + 1;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
} else if (p < m) {
|
||
|
|
num2 += num1;
|
||
|
|
den2 += den1;
|
||
|
|
} else {
|
||
|
|
num1 += num2;
|
||
|
|
den1 += den2;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (den1 > precision) {
|
||
|
|
den1 = den2;
|
||
|
|
num1 = num2;
|
||
|
|
}
|
||
|
|
return new Fraction(num1, den1);
|
||
|
|
}
|
||
|
|
|