="w"> </span><span class="n">datan2</span><span class="p">(</span><span class="n">xr</span><span class="p">,</span><span class="mf">1.0d0</span><span class="p">)</span>
<span class="w">      </span><span class="n">yi</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0.0d0</span>
<span class="w">   </span><span class="k">elseif</span><span class="w"> </span><span class="p">(</span><span class="n">xr</span><span class="p">.</span><span class="n">ne</span><span clas