keyword">if</span> (alp1*alp2 &gt; 0)
0207       alp0 = alp1;    <span class="comment">% default if minimizer does not exist</span>
0208       denom = (f-f1)/(alp-alp1)-(f-f2)/(alp-alp2);
0209       <span class="keyword">if</span> (denom &gt; 0)
0210         alp0 = 0.5*(alp1+alp2-(f1-f2)/denom);
0211       <span class="keyword">end</span>
0212     <span class="keyword">end</span>
0213     
0214     <span class="comment">% compute Goldstein quotient</span>
0215     mu = (f-f0)/(alp*pi0);
0216     <span class