couchdb/userdata/_design/heatmap/views/by_episode/reduce.js

   1 function (keys, values, rereduce)
   2 {
   3     function unique(arr) {
   4         var a = [];
   5         var l = arr.length;
   6         for(var i=0; i<l; i++) {
   7             for(var j=i+1; j<l; j++) {
   8                 if (arr[i] === arr[j])
   9                     j = ++i;
  10             }
  11             a.push(arr[i]);
  12         }
  13         return a;
  14     };
  15
  16     function flatten(arr)
  17     {
  18         var flattened = []
  19         for(var n in arr)
  20         {
  21             for(var x in arr[n])
  22             {
  23                 flattened.push(arr[n][x]);
  24             }
  25         }
  26         return flattened
  27     };
  28
  29     function sortNumerical(a, b)
  30     {
  31         if(a < b)
  32         {
  33             return -1;
  34         }
  35         else if (a > b)
  36         {
  37             return 1;
  38         }
  39         else
  40         {
  41             return 0;
  42         }
  43     };
  44
  45     function mergeBorders(borders, maxBorders)
  46     {
  47         last = null;
  48         newBorders = [];
  49
  50         lastBorder = borders[borders.length-1];
  51         minDist = lastBorder / maxBorders;
  52
  53         for(var n in borders)
  54         {
  55             border = borders[n];
  56
  57             if(last == null)
  58             {
  59             }
  60             else if (border == lastBorder)
  61             {
  62             }
  63             else if ((border - last) < minDist)
  64             {
  65                 continue;
  66             }
  67
  68             newBorders.push(border);
  69             last = border;
  70         }
  71
  72         return newBorders;
  73     };
  74
  75     var all_borders = [];
  76
  77     if (rereduce)
  78     {
  79         for(var n in values)
  80         {
  81             all_borders.push(values[n].borders);
  82         }
  83     }
  84     else
  85     {
  86         all_borders = values;
  87     }
  88
  89     var borders = flatten(all_borders);
  90     borders = unique(borders);
  91     borders.sort(sortNumerical);
  92     borders = mergeBorders(borders, 50);
  93
  94     var heatmap = [];
  95
  96     for(var n=0; n<borders.length-1; n++)
  97     {
  98         heatmap.push(0);
  99     }
 100
 101     for(var n in values)
 102     {
 103         j = 0;
 104         var length = 0;
 105         var increment = 1;
 106
 107         if(rereduce)
 108         {
 109             length = values[n].borders.length-1;
 110             increment = 1;
 111         }
 112         else
 113         {
 114             length = values[n].length;
 115             increment = 2;
 116         }
 117
 118
 119         for(var i=0; i<length; i+=increment)
 120         {
 121             var from = 0;
 122             var until = 0;
 123
 124             if(rereduce)
 125             {
 126                 from  = values[n].borders[i];
 127                 until = values[n].borders[i+1];
 128             }
 129             else
 130             {
 131                 from  = values[n][i];
 132                 until = values[n][i+1];
 133             }
 134
 135             while(borders[j] < from)
 136             {
 137                 j++;
 138             }
 139
 140             while(borders[j] < until)
 141             {
 142                 if(rereduce)
 143                 {
 144                     heatmap[j++] += values[n].heatmap[i];
 145                 }
 146                 else
 147                 {
 148                     heatmap[j++] += 1;
 149                 }
 150             }
 151         }
 152     }
 153
 154     return {heatmap: heatmap, borders: borders};
 155 }