whatever

function KNN(kSize){
  this.kSize = kSize;
  this.points = [];
}

KNN.prototype.train = function(set){
  this.points = this.points.concat(set)
}

KNN.prototype._distance =function(p1,p2){
  var d = 0
  for(var i = 0;i<p1.length;i++){
    d+=Math.pow(p1[i]-p2[i],2)
  }
  return Math.sqrt(d)
}

KNW.prototype._distances = function(p){
  var self = this;
  var points = this.points.map(v=>{
    return [self._distance(p,v[0]),v[1]]
  }).sort((a,b)=>(a[0] - b[0]))
  return points.splice(0,this.kSize)
}

Array.prototype.count = function(v){
  var c = 0
  for(var i =0;i<this.length;i++){
    if(this[i]===v) c++
  }
  return c;
}

KNW.prototype._classify = function(closestNeighbors){
  var classesCount = closestNeighbors.map(v=>this.count(v));
  var max = Math.max.apply(null,classesCount)
  return closestNeighbors[classesCount.indexOf(max)]
}