public static double distanceTo(double x1,double y1,double z1,double x2,double y2,double z2){
  final double a=x1 - x2;
  final double b=y1 - y2;
  final double c=z1 - z2;
  return Math.sqrt(a * a + b * b + c * c);
}

public static double distanceTo ( double x1 , double y1 , double z1 , double x2 , double y2 , double z2 ) { final double a = x1 - x2 ; final double b = y1 - y2 ; final double c = z1 - z2 ; return Math . sqrt ( a * a + b * b + c * c ) ; }
computes the euclidean length between two points .
