an class="w"> </span><span class="n">an</span><span class="o">*</span><span class="n">Ppar</span>
<span class="w">                     </span><span class="n">sd</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">SQRT</span><span class="p">(</span><span class="n">an</span><span class="o">*</span><span class="n">Ppar</span><span class="o">*</span><span class="p">(</span><span class="mf">1.0_wp</span><span class="o">-</span><span class="n">Ppar</span><span class="p">