source code
// The Computer Language Benchmarks Game
// http://benchmarksgame.alioth.debian.org/
//
// Contributed by Ian Osgood
// Largely rewritten by Matthew Wilson
function fastaRepeat(n, seq) {
var seqi = 0, len = seq.length, i, j, k, l, block,
str = Array(len*60+1).join(seq), lines = Array(i=j=len*len);
while (--j>-1) { lines[j] = str.substr(60*j, 60) }
block = lines.join("\n");
for (j=0, k=Math.floor((l=Math.floor(n/60))/i); j<k; ++j) { console.log(block) }
for (j = 0, k = l % i; j < k; ++j) { console.log(lines[j]) }
if (n % 60 > 0) { console.log(lines[k].substr(0, n % 60)) }
}
var rand=(function() {
var Last = 42;
return function() { return (Last=(Last * 3877 + 29573) % 139968) / 139968 }
})();
function printLineMaker(table) {
var h = 0, k = [], v = [], c, l=0;
for (c in table) { l = v[h] = table[k[h++] = c]+=l; }
return function(x) {
var line = "";
next: for (var i=0; i<x; ++i) {
var r = rand(), j=0;
for (;;++j) {
if (r < v[j]) {
line += k[j];
continue next;
}
}
}
console.log(line);
}
}
function fastaRandom(n, table) {
var printLine=printLineMaker(table);
while ((n -= 60) > -1) { printLine(60) }
if (n<0 && n>-60) { printLine(60 + n) }
}
(function main(n) {
var ALU = "GGCCGGGCGCGGTGGCTCACGCCTGTAATCCCAGCACTTTGG" +
"GAGGCCGAGGCGGGCGGATCACCTGAGGTCAGGAGTTCGAGA" +
"CCAGCCTGGCCAACATGGTGAAACCCCGTCTCTACTAAAAAT" +
"ACAAAAATTAGCCGGGCGTGGTGGCGCGCGCCTGTAATCCCA" +
"GCTACTCGGGAGGCTGAGGCAGGAGAATCGCTTGAACCCGGG" +
"AGGCGGAGGTTGCAGTGAGCCGAGATCGCGCCACTGCACTCC" +
"AGCCTGGGCGACAGAGCGAGACTCCGTCTCAAAAA";
var IUB = { a:0.27, c:0.12, g:0.12, t:0.27, B:0.02, D:0.02, H:0.02, K:0.02,
M:0.02, N:0.02, R:0.02, S:0.02, V:0.02, W:0.02, Y:0.02 }
var HomoSap = {
a:0.3029549426680, c:0.1979883004921, g:0.1975473066391, t:0.3015094502008
}
console.log(">ONE Homo sapiens alu")
fastaRepeat(2*n, ALU)
console.log(">TWO IUB ambiguity codes")
fastaRandom(3*n, IUB)
console.log(">THREE Homo sapiens frequency")
fastaRandom(5*n, HomoSap)
}).call(this, +process.argv[2])