1// The Great Computer Language Shootout
2//  http://shootout.alioth.debian.org
3//
4//  Contributed by Ian Osgood
5
6var last = 42, A = 3877, C = 29573, M = 139968;
7
8function rand(max) {
9  last = (last * A + C) % M;
10  return max * last / M;
11}
12
13var ALU =
14  "GGCCGGGCGCGGTGGCTCACGCCTGTAATCCCAGCACTTTGG" +
15  "GAGGCCGAGGCGGGCGGATCACCTGAGGTCAGGAGTTCGAGA" +
16  "CCAGCCTGGCCAACATGGTGAAACCCCGTCTCTACTAAAAAT" +
17  "ACAAAAATTAGCCGGGCGTGGTGGCGCGCGCCTGTAATCCCA" +
18  "GCTACTCGGGAGGCTGAGGCAGGAGAATCGCTTGAACCCGGG" +
19  "AGGCGGAGGTTGCAGTGAGCCGAGATCGCGCCACTGCACTCC" +
20  "AGCCTGGGCGACAGAGCGAGACTCCGTCTCAAAAA";
21
22var IUB = {
23  a:0.27, c:0.12, g:0.12, t:0.27,
24  B:0.02, D:0.02, H:0.02, K:0.02,
25  M:0.02, N:0.02, R:0.02, S:0.02,
26  V:0.02, W:0.02, Y:0.02
27}
28
29var HomoSap = {
30  a: 0.3029549426680,
31  c: 0.1979883004921,
32  g: 0.1975473066391,
33  t: 0.3015094502008
34}
35
36function makeCumulative(table) {
37  var last = null;
38  for (var c in table) {
39    if (last) table[c] += table[last];
40    last = c;
41  }
42}
43
44function fastaRepeat(n, seq) {
45  var seqi = 0, lenOut = 60;
46  while (n>0) {
47    if (n<lenOut) lenOut = n;
48    if (seqi + lenOut < seq.length) {
49      ret = seq.substring(seqi, seqi+lenOut);
50      seqi += lenOut;
51    } else {
52      var s = seq.substring(seqi);
53      seqi = lenOut - s.length;
54      ret = s + seq.substring(0, seqi);
55    }
56    n -= lenOut;
57  }
58}
59
60function fastaRandom(n, table) {
61  var line = new Array(60);
62  makeCumulative(table);
63  while (n>0) {
64    if (n<line.length) line = new Array(n);
65    for (var i=0; i<line.length; i++) {
66      var r = rand(1);
67      for (var c in table) {
68        if (r < table[c]) {
69          line[i] = c;
70          break;
71        }
72      }
73    }
74    ret = line.join('');
75    n -= line.length;
76  }
77}
78
79var ret;
80
81var count = 7;
82ret = fastaRepeat(2*count*100000, ALU);
83ret = fastaRandom(3*count*1000, IUB);
84ret = fastaRandom(5*count*1000, HomoSap);
85
86