1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
|
/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
//-----------------------------------------------------------------------------
var BUGNUMBER = 363040;
var summary = 'Array.prototype.reduce application in continued fraction';
var actual = '';
var expect = '';
//-----------------------------------------------------------------------------
test();
//-----------------------------------------------------------------------------
function test()
{
printBugNumber(BUGNUMBER);
printStatus (summary);
// Print x as a continued fraction in compact abbreviated notation and return
// the convergent [n, d] such that x - (n / d) <= epsilon.
function contfrac(x, epsilon) {
let i = Math.floor(x);
let a = [i];
x = x - i;
let maxerr = x;
while (maxerr > epsilon) {
x = 1 / x;
i = Math.floor(x);
a.push(i);
x = x - i;
maxerr = x * maxerr / i;
}
print(a);
return a.reduceRight(function (x, y) {return [x[0] * y + x[1], x[0]];}, [1, 0]);
}
if (!Array.prototype.reduceRight)
{
print('Test skipped. Array.prototype.reduceRight not implemented');
}
else
{
// Show contfrac in action on some interesting numbers.
for (num of [Math.PI, Math.sqrt(2), 1 / (Math.sqrt(Math.E) - 1)]) {
print('Continued fractions for', num);
for (eps of [1e-2, 1e-3, 1e-5, 1e-7, 1e-10]) {
let frac = contfrac(num, eps);
let est = frac[0] / frac[1];
let err = num - est;
print(frac, est, err);
}
print();
}
}
reportCompare(expect, actual, summary);
}
|
