pan><span class="w"> </span><span class="nb">ATAN</span><span class="p">(</span><span class="n">Y1</span><span class="p">(</span><span class="n">i</span><span class="p">)</span><span class="o">/</span><span class="n">Y2</span><span class="p">(</span><span class="n">i</span><span class="p">))</span>
<span class="w">         </span><span class="k">ENDDO</span>
<span class="k">         CALL </span><span class="n">PLOTX</span><span class="p">(</span><span class="n">Z</span><span class="p">,</span><span class="n