<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><div id="yiv1817800098"><table cellspacing="0" cellpadding="0" border="0" id="bodyDrftID" class=""><tbody><tr><td id="drftMsgContent" style="font:inherit;">Hello Everyone,<div><br></div><div>I have a weird problem with IPOPT using GAMS Interface. My problem is an non linear problem. I tried to resolve it on real instances but I got errors of the system. So I reduced my instances to a problem of small size which can be solved with a pen and a paper.However I still have an error system. I reproduce at the end of this message the solution report :</div><div><div><br></div><div>I try to solve it with COUENNE and I get my solution. I tried with BONMIN ( I cheated, I toldBONMIN that my problem was MINLP) BONMIN called Ipopt and we get the same error sytem.</div><div><br></div><div>I am a bit stubborn, so I would like to see if the
problem was coming from GAMS. I used CONVERT to transpose my instance into AMPL format. I tried and IPOPT achieve maximum of iterations. BONMIN and COUENNE find quickly the solution of my problem.</div><div><br></div><div>Have you got any ideas to solve this kind of problem.</div><div><br></div><div>Best Regards, </div><div>Dan</div><div><br></div><div><br></div><div><br></div><div><br></div><div><div>**********************************************************************************************************</div><div>**********************************************************************************************************</div><div>MODEL STATISTICS</div><div><br></div><div>BLOCKS OF EQUATIONS 3 SINGLE EQUATIONS 12</div><div>BLOCKS OF VARIABLES 5 SINGLE VARIABLES 41 6
projected</div><div>NON ZERO ELEMENTS 78 NON LINEAR N-Z 69</div><div>DERIVATIVE POOL 16 CONSTANT POOL 19</div><div>CODE LENGTH 377</div><div><br></div><div><br></div><div>GENERATION TIME = 0.125 SECONDS 4 Mb WIN233-233 Dec 15, 2009</div><div><br></div><div><br></div><div>EXECUTION TIME = 0.219 SECONDS 4 Mb WIN233-233 Dec 15, 2009</div><div>GAMS Rev 233 WIN-VIS 23.3.3 x86/MS Windows 05/27/10 09:13:46 Page 7</div><div>G e n e r a l A l g e b r a i c M o d e l i n g S y s t e
m</div><div>Solution Report SOLVE min_Master_1 Using DNLP From line 406</div><div><br></div><div><br></div><div> S O L V E S U M M A R Y</div><div><br></div><div> MODEL min_Master_1 OBJECTIVE f_obj</div><div> TYPE DNLP DIRECTION MINIMIZE</div><div> SOLVER COINIPOPT FROM LINE 406</div><div><br></div><div>**** SOLVER STATUS 13 System Failure </div><div>**** MODEL STATUS 13 Error No Solution </div><div>**** OBJECTIVE VALUE NA</div><div><br></div><div> RESOURCE USAGE, LIMIT NA
1000.000</div><div> ITERATION COUNT, LIMIT NA 2000000000</div><div> EVALUATION ERRORS NA 0</div><div><br></div><div>GAMS/CoinIpopt NLP Solver (IPOPT Library 3.7)</div><div>written by A. Waechter</div><div><br></div><div>List of user-set options:</div><div><br></div><div> Name Value used</div><div> max_cpu_time = 300 yes</div><div><br></div><div>******************************************************************************</div><div>This
program contains Ipopt, a library for large-scale nonlinear optimization.</div><div> Ipopt is released as open source code under the Common Public License (CPL).</div><div> For more information visit http://projects.coin-or.org/Ipopt</div><div>******************************************************************************</div><div><br></div><div>NOTE: You are using Ipopt by default with the MUMPS linear solver.</div><div> Other linear solvers might be more efficient (see Ipopt documentation).</div><div><br></div><div><br></div><div>Exception of type: IpoptException in file "Unknown File" at line -1:</div><div> Exception message: Unknown Exception caught in Ipopt</div><div><br></div><div>No solution
returned</div><div>**********************************************************************************************************</div><div>**********************************************************************************************************</div><div><br></div></div></div></td></tr></tbody></table></div></td></tr></table><br>