<div>Hello everyone</div>
<div> </div>
<div>I tried the following problem:</div>
<div> </div>
<div><font color="#ff6600">function Integral1(Reals,Reals,Reals);<br>var x ;<br>var y ;<br>minimize Z:tan(x)+y*Integral1(x,0,1);<br>subject to constrain:x+y>=5;<br>subject to constraint:2*x+3*y<=27;<br>option solver ipopt;
<br>solve;<br>display x;<br>display y;<br>display Z;</font></div>
<div><font color="#ff6600"><br></font><font color="#000000">When the solver option was chosen "ipopt" as above, I got the following solution:</font></div>
<div><font color="#3333ff">EXIT: Optimal Solution Found.<br>Ipopt 3.2.2: Optimal Solution Found<br>x = -12</font></div>
<div><font color="#3333ff">y = 17</font></div>
<div><font color="#3333ff">Z = 7.41788</font></div>
<div><font color="#3333ff"><font color="#000000">When the solver option was chosen "bonmin" and every parameter in bonmin remains default, I got the following:</font></font></div>
<div><font color="#3333ff">
<p><font color="#ff0000">bonmin: <br>******************************************************************************<br>This program contains Ipopt, a library for large-scale nonlinear optimization.<br> Ipopt is released as open source code under the Common Public License (CPL).
<br> For more information visit </font><a href="http://projects.coin-or.org/Ipopt"><font color="#ff0000">http://projects.coin-or.org/Ipopt</font></a><br><font color="#ff0000">******************************************************************************
</font></p>
<p><font color="#ff0000">Ipopt exited with error code -2 Restoration Failed<br>Error in opening Names file (probably does not exists)can't open /tmp/at2970.sol</font></p>
<p><font color="#ff0000"><font color="#000000">Note: Integral1() is the external function I defined by myself. Actually I tried all of the four algorithms in bonmin, one of them works.</font></font></p>
<p><font color="#000000">Why the two outputs are so different? Anyone has some idea?</font></p>
<p><font color="#000000">Thanks</font></p><font color="#000000"></font></font></div>
<div><font color="#3333ff"><font color="#000000">Roy</font><font color="#ff0000">
<p><br></p></font><br> </font></div>
<div> </div>