</sup></strong></span></em></span> spherical coordinates.
      </p>
<p>
        <a name="boost_quaternions.quaternions.creation_semipolar"></a> <code class="computeroutput"><span class="identifier">semipolar</span></code> is another generator which is
        specific to quaternions. It takes as a first input the magnitude of the quaternion,
        as a second input an angle in the range <code class="computeroutput"><span class="number">0</span></code>
        to <code class="computeroutput"><span class="