@Override public double calculateDistance(double[] x1,double[] x2){
  return (Math.exp(this.gamma * norm2(x1,x2)));
}

@ Override public double calculateDistance ( double [ ] x1 , double [ ] x2 ) { return ( Math . exp ( this . gamma * norm2 ( x1 , x2 ) ) ) ; }
calculates kernel value of vectors x and y .
