="o">**</span><span class="n">cHK</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span>

            <span class="c1"># calculate hue angle:</span>
            <span class="n">h</span> <span class="o">=</span> <span class="n">hue_angle</span><span class="p">(</span><span class="n">a</span><span class="p">,</span><span class="n">b</span><span class="p">,</span> <span class="n">htype</span> <span class="o">=</span> <span class="s1">&#39;rad&#39;</span><span class="p">)</span>
       