ith the usual spherical coordinates in <span class="emphasis"><em><span class="bold"><strong>R<sup>3</sup></strong></span></em></span>).
        Due to the many symmetries and periodicities, nothing untoward happens if
        the magnitude is negative or the angles are outside their natural ranges.
        The expected degeneracies (a magnitude of zero ignores the angles settings...)
        do happen however.
      </p>
<p>
        <a name="boost_quaternions.quaternions.creation_cylindrical"></a> <code cl