Javascript Array percentile(cents,get,comp)

Array.prototype.percentile = function(cents,get,comp) {
 get  = typeof get  === "function" ? get  : function(a){return a};
 comp = typeof comp === "function" ? comp : function(a,b){return a-b};
 var sort = this.map(get).sort(comp),
     len  = sort.length,/*from ww  w  . j a v a2s . c o m*/
     min  = sort[0],
     max  = sort[len-1],
     one  = (max-min)/100,
     out  = [];

 for(var i=0; i<len; i++) {
  
 }
 return out;
}