><span class="identifier">phi</span><span class="special">);</span>

<span class="identifier">point_t</span> <span class="identifier">point_on_sphere</span><span class="special">(</span><span class="identifier">sin_theta</span><span class="special">*</span><span class="identifier">sin_phi</span><span class="special">,</span> <span class="identifier">cos_theta</span><span class="special">,</span> <span class="identifier">sin_theta</span><span class="special">*</span><span class="identifier">cos_phi</span><sp