2);
0391         fact = (alp1/alp2)^(1/3);
0392         <span class="keyword">if</span> (0)      <span class="comment">%/*_isnan(f1)*/</span>
0393           <span class="comment">% f1=NaN, take a short interior step</span>
0394           alpd = fact*alp2;
0395         <span class="keyword">else</span>
0396           <span class="comment">% f1 is a valid number or infinite</span>
0397           <span class="keyword">if</span> (alpd&lt;fact*alp2)
0398             <span class="comment">% cut interpolation step