/**
* Simply returns {@code log(a. inverse() * b)}.
*
* <p>Useful for {@link #squadTangent(Quaternion, Quaternion, Quaternion)}.
*
* @param a the first Quaternion
* @param b the second Quaternion
*/
public static final Quaternion lnDif(Quaternion a, Quaternion b) {
Quaternion dif = a.inverse();
dif.multiply(b);
dif.normalize();
return dif.log();
}
