// Distance computes the distance from this FieldPoint to point p.
public double Distance(FieldPoint p)
{
double x = (p.X - X);
double y = (p.Y - Y);
double z = (p.Z - Z);
return Math.Sqrt(x * x + y * y + z * z);
}
// Angle computes the angel between left, right, and p, with p the
// vertext of the angle.
public double Angle(FieldPoint left, FieldPoint right, FieldPoint p)
{
double b = right.Distance(p);
double a = left.Distance(p);
double width = right.Distance(left);
double C = Math.Acos((a * a + b * b - width * width) / (2 * a * b));
// C = C * 180.0 / PI; // convert to degrees
return C;
}