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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Dear developers,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I am trying to solve a constrained NLP, where the starting point x0 satisfies all the constraints but it is far to be an optimum. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have set options.ipopt to the default values, except for options.ipopt.hessian_approximation = 'limited-memory'. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>IPOPT exits without modifying x0 with info.status=5 (user requested stop).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I would appreciate your help to understand why this happens.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Yours,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=ES style='color:#1F497D'>Prof. Dr. Víctor D. Fachinotti</span><span lang=ES><o:p></o:p></span></p><p class=MsoNormal><span lang=ES-AR style='color:#1F497D'>Centro de Investigación de Métodos Computacionales (CIMEC)</span><span lang=ES><o:p></o:p></span></p><p class=MsoNormal><span lang=ES-AR style='color:#1F497D'>Universidad Nacional del Litoral (UNL)</span><span lang=ES><o:p></o:p></span></p><p class=MsoNormal><span lang=ES-AR style='color:#1F497D'>Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) </span><span lang=ES><o:p></o:p></span></p><p class=MsoNormal><span lang=ES style='color:#1F497D'>Predio CONICET “Dr. Alberto Cassano”</span><span lang=ES><o:p></o:p></span></p><p class=MsoNormal><span lang=ES style='color:#1F497D'>Colectora Ruta Nac. 168 s/n, Paraje El Pozo</span><span lang=ES><o:p></o:p></span></p><p class=MsoNormal><span lang=ES style='color:#1F497D'>3000, Santa Fe, Argentina</span><span lang=ES><o:p></o:p></span></p><p class=MsoNormal><span lang=ES style='color:#1F497D'>Tel: +54 342 4511594 x 7045</span><span lang=ES><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Fax: +54 342 4511169<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>PS: These are the messages I got:<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal>This is Ipopt version 3.11.8, running with linear solver ma57.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Number of nonzeros in equality constraint Jacobian...: 9701<o:p></o:p></p><p class=MsoNormal>Number of nonzeros in inequality constraint Jacobian.: 3200<o:p></o:p></p><p class=MsoNormal>Number of nonzeros in Lagrangian Hessian.............: 0<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Reallocating memory for MA57: lfact (155793)<o:p></o:p></p><p class=MsoNormal>Reallocating memory for MA57: lfact (324812)<o:p></o:p></p><p class=MsoNormal>Reallocating memory for MA57: lfact (493001)<o:p></o:p></p><p class=MsoNormal>Reallocating memory for MA57: lfact (681090)<o:p></o:p></p><p class=MsoNormal>Reallocating memory for MA57: lfact (2385003)<o:p></o:p></p><p class=MsoNormal>Reallocating memory for MA57: lfact (3591894)<o:p></o:p></p><p class=MsoNormal>Reallocating memory for MA57: lfact (7330350)<o:p></o:p></p><p class=MsoNormal>Reallocating memory for MA57: lfact (8969064)<o:p></o:p></p><p class=MsoNormal>Total number of variables............................: 6518<o:p></o:p></p><p class=MsoNormal> variables with only lower bounds: 0<o:p></o:p></p><p class=MsoNormal> variables with lower and upper bounds: 6518<o:p></o:p></p><p class=MsoNormal> variables with only upper bounds: 0<o:p></o:p></p><p class=MsoNormal>Total number of equality constraints.................: 3318<o:p></o:p></p><p class=MsoNormal>Total number of inequality constraints...............: 1<o:p></o:p></p><p class=MsoNormal> inequality constraints with only lower bounds: 0<o:p></o:p></p><p class=MsoNormal> inequality constraints with lower and upper bounds: 0<o:p></o:p></p><p class=MsoNormal> inequality constraints with only upper bounds: 1<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=FR>iter objective inf_pr inf_du lg(mu) ||d|| lg(rg) alpha_du alpha_pr ls<o:p></o:p></span></p><p class=MsoNormal><span lang=FR> </span><span lang=ES>0 8.2501468e-002 5.41e-013 1.00e+000 0.0 0.00e+000 - 0.00e+000 0.00e+000 0<o:p></o:p></span></p><p class=MsoNormal><span lang=ES><o:p> </o:p></span></p><p class=MsoNormal><span lang=ES>Number of Iterations....: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=ES><o:p> </o:p></span></p><p class=MsoNormal><span lang=ES> </span>(scaled) (unscaled)<o:p></o:p></p><p class=MsoNormal>Objective...............: 8.2501467997805847e-002 8.2501467997805847e-002<o:p></o:p></p><p class=MsoNormal><span lang=ES>Dual infeasibility......: 1.0000000000000000e+000 1.0000000000000000e+000<o:p></o:p></span></p><p class=MsoNormal><span lang=ES>Constraint violation....: 5.4107912499765483e-013 5.4107912499765483e-013<o:p></o:p></span></p><p class=MsoNormal><span lang=ES>Complementarity.........: 1.8929389054602732e+000 1.8929389054602732e+000<o:p></o:p></span></p><p class=MsoNormal><span lang=ES>Overall NLP error.......: 1.8929389054602732e+000 1.8929389054602732e+000<o:p></o:p></span></p><p class=MsoNormal><span lang=ES><o:p> </o:p></span></p><p class=MsoNormal><span lang=ES><o:p> </o:p></span></p><p class=MsoNormal>Number of objective function evaluations = 1<o:p></o:p></p><p class=MsoNormal>Number of objective gradient evaluations = 1<o:p></o:p></p><p class=MsoNormal>Number of equality constraint evaluations = 1<o:p></o:p></p><p class=MsoNormal>Number of inequality constraint evaluations = 1<o:p></o:p></p><p class=MsoNormal>Number of equality constraint Jacobian evaluations = 1<o:p></o:p></p><p class=MsoNormal>Number of inequality constraint Jacobian evaluations = 1<o:p></o:p></p><p class=MsoNormal>Number of Lagrangian Hessian evaluations = 0<o:p></o:p></p><p class=MsoNormal>Total CPU secs in IPOPT (w/o function evaluations) = 0.493<o:p></o:p></p><p class=MsoNormal>Total CPU secs in NLP function evaluations = 0.010<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>EXIT: Stopping optimization at current point as requested by user.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>