a simulation for discussion 11 problem 3 in data analysis packet B, tjhsst 2013-14. it generates 4000 heads/tails combinations and counts how many appear consecutively, and how many times. to run, copy and paste this into a javascript console to run, i wrote it rather quickly!

consecutiveheadstails.js

var arr = [];
for (var i = 0; i < 4000; i++) {
  if (Math.random() < 0.5) arr.push("H");
  else arr.push("T");
}
var str = arr.join("");
var bla = str.match(/(H+|T+)/g);
var tab = {};
for (var i = 0; i < bla.length; i++) {
  if (typeof tab[bla[i]] == "undefined") {
    tab[bla[i]] = 1;
  } else {
    tab[bla[i]]++;
  }
}
console.log(tab);