## individual methods

## complete sfrotation class

This class can represent a 3D rotation. The class has 4 double numbers which
represent the rotation as either quaternion, axis-angle or euler number depending
on the cde int/enum

The class has methods to combine with other rotations. Also many other methods,
including the ability to load and save to from VRML and x3d

There are 3 versions available depending on language:

See also the following related classes

- sfvec2f
- sfvec3f
- sfrotation
- sftranslation
- sfmulti3d

The full source code is available on Sourceforge here:

## Conjugate

public final void conjugate(Quat4d q1) {

x = -q1.x;

y = -q1.y;

z = -q1.z;

w = q1.w;

}

## Normalising Quaternions

public final void normalise() {

double n = Math.sqrt(x*x + y*y + z*z + w*w);

x /= n;

y /= n;

z /= n;

w /= n;

}

## Quaternion Scalar Multiplication

public final void scale(double s){

x *= s;

y *= s;

z *= s;

w *= s;

}