Shuffle Visualizer: Visual sanity-check for randomness in deck-shuffling algorithms (JS and CoffeeScript versions)

shuffle-visualizer.coffee

#Usage:
#1. Declare your shuffle() function. No parameters necessary, since `deck` is a global variable.
#2. Run `test()`.

deckSize = 52
deck = [0...deckSize]
 
rand = (min = 0, max = deckSize) ->
  Math.floor(Math.random() * (max - min)) + min
 
swap = (a, b) ->
  if a isnt b then [deck[a], deck[b]] = [deck[b], deck[a]]
 
testCount = 10000

log2 = (x) -> 
	Math.log(x) / Math.LN2

test = (document = document) ->    
    plot do () ->
        for [1..testCount]
            deck = [0...deckSize]
            do shuffle    
            for i in [0...deckSize]
                if deck.indexOf(i) is -1 then throw "#{i} is not in the deck"
                if deck.length isnt deckSize then throw "deck length is #{deck.length}; should be #{deckSize}"  
            deck
       
plot = (runs) ->    
    values = ((0 for [0...deckSize]) for [0...deckSize])

    for run in runs  
        for card, index in run
            values[card][index]++
    
    #rescale the values to the 0..255 range
    maxValue = values.reduce((prev, arr) ->
      Math.max(prev, Math.max.apply(null, arr))
    , 0)

    proportion = 255 / maxValue
     
    #create a table
    table = document.createElement "table"
    document.getElementsByTagName("body")[0].appendChild(table)
    
    #top row
    row = document.createElement "tr"
    table.appendChild row
    
    #column headers
    for k in [0...deckSize]
        th = document.createElement "th"
        th.appendChild document.createTextNode k
        row.appendChild th
    
    for i in [0...deckSize]    
        #current row
        row = document.createElement "tr"
        table.appendChild row
        
        #row header
        th = document.createElement "th"
        th.appendChild document.createTextNode i
        row.appendChild th
        
        for v in values[i]
            #calculate brigtness value
            j = Math.floor(v * proportion)
            
            #add table cell
            td = document.createElement 'td'
            td.style.cssText = "background-color:rgb(#{j},#{j},#{j});"
            row.appendChild td

shuffle-visualizer.js

//Usage:
//1. Declare your shuffle() function. No parameters necessary, since `deck` is a global variable.
//2. Run `test()`.

var deck, deckSize, l, log2, plot, rand, results, swap, test, testCount;

deckSize = 52;

deck = (function() {
  results = [];
  for (var l = 0; 0 <= deckSize ? l < deckSize : l > deckSize; 0 <= deckSize ? l++ : l--){ results.push(l); }
  return results;
}).apply(this);

rand = function(min, max) {
  if (min == null) {
    min = 0;
  }
  if (max == null) {
    max = deckSize;
  }
  return Math.floor(Math.random() * (max - min)) + min;
};

swap = function(a, b) {
  var ref;
  if (a !== b) {
    return ref = [deck[b], deck[a]], deck[a] = ref[0], deck[b] = ref[1], ref;
  }
};

testCount = 10000;

log2 = function(x) {
  return Math.log(x) / Math.LN2;
};

test = function(document) {
  if (document == null) {
    document = document;
  }
  return plot((function() {
    var i, m, n, o, ref, ref1, results1, results2;
    results1 = [];
    for (m = 1, ref = testCount; 1 <= ref ? m <= ref : m >= ref; 1 <= ref ? m++ : m--) {
      deck = (function() {
        results2 = [];
        for (var n = 0; 0 <= deckSize ? n < deckSize : n > deckSize; 0 <= deckSize ? n++ : n--){ results2.push(n); }
        return results2;
      }).apply(this);
      shuffle();
      for (i = o = 0, ref1 = deckSize; 0 <= ref1 ? o < ref1 : o > ref1; i = 0 <= ref1 ? ++o : --o) {
        if (deck.indexOf(i) === -1) {
          throw i + " is not in the deck";
        }
        if (deck.length !== deckSize) {
          throw "deck length is " + deck.length + "; should be " + deckSize;
        }
      }
      results1.push(deck);
    }
    return results1;
  })());
};

plot = function(runs) {
  var card, i, index, j, k, len, len1, m, maxValue, n, o, p, proportion, ref, ref1, results1, row, run, table, td, th, v, values;
  values = (function() {
    var m, ref, results1;
    results1 = [];
    for (m = 0, ref = deckSize; 0 <= ref ? m < ref : m > ref; 0 <= ref ? m++ : m--) {
      results1.push((function() {
        var n, ref1, results2;
        results2 = [];
        for (n = 0, ref1 = deckSize; 0 <= ref1 ? n < ref1 : n > ref1; 0 <= ref1 ? n++ : n--) {
          results2.push(0);
        }
        return results2;
      })());
    }
    return results1;
  })();
  for (m = 0, len = runs.length; m < len; m++) {
    run = runs[m];
    for (index = n = 0, len1 = run.length; n < len1; index = ++n) {
      card = run[index];
      values[card][index]++;
    }
  }
  maxValue = values.reduce(function(prev, arr) {
    return Math.max(prev, Math.max.apply(null, arr));
  }, 0);
  proportion = 255 / maxValue;
  table = document.createElement("table");
  document.getElementsByTagName("body")[0].appendChild(table);
  row = document.createElement("tr");
  table.appendChild(row);
  for (k = o = 0, ref = deckSize; 0 <= ref ? o < ref : o > ref; k = 0 <= ref ? ++o : --o) {
    th = document.createElement("th");
    th.appendChild(document.createTextNode(k));
    row.appendChild(th);
  }
  results1 = [];
  for (i = p = 0, ref1 = deckSize; 0 <= ref1 ? p < ref1 : p > ref1; i = 0 <= ref1 ? ++p : --p) {
    row = document.createElement("tr");
    table.appendChild(row);
    th = document.createElement("th");
    th.appendChild(document.createTextNode(i));
    row.appendChild(th);
    results1.push((function() {
      var len2, q, ref2, results2;
      ref2 = values[i];
      results2 = [];
      for (q = 0, len2 = ref2.length; q < len2; q++) {
        v = ref2[q];
        j = Math.floor(v * proportion);
        td = document.createElement('td');
        td.style.cssText = "background-color:rgb(" + j + "," + j + "," + j + ");";
        results2.push(row.appendChild(td));
      }
      return results2;
    })());
  }
  return results1;
};

// ---
// generated by coffee-script 1.9.2