1 d3.min = function(array, f) {

     2   var i = -1,

     3       n = array.length,

     4       a,

     5       b;

     6   if (arguments.length === 1) {

     7     while (++i < n && ((a = array[i]) == null || a != a)) a = undefined;

     8     while (++i < n) if ((b = array[i]) != null && a > b) a = b;

     9   } else {

    10     while (++i < n && ((a = f.call(array, array[i], i)) == null || a != a)) a = undefined;

    11     while (++i < n) if ((b = f.call(array, array[i], i)) != null && a > b) a = b;

    12   }

    13   return a;

    14 };