code: function points_eq(a,b,precision){
      return scalar_eq(a[0],b[0],precision) && scalar_eq(a[1],b[1],precision);
  }
docs: Check if two points are equal
  @static
  @method points_eq
  @param  {Array} a
  @param  {Array} b
  @param  {Number} [precision]
  @return {Boolean}