<div dir="ltr">Hi guys,<div><br></div><div>I am trying to solve a NLP problem. </div><div><br></div><div>min f(x)</div><div>s.t. </div><div><br></div><div>g(x,p_i)=0 \forall i=1...N_s</div><div>h(x)>=0</div><div><br></div>
<div><div>where x represents control variables and p_i represents the i-th set of parameters.</div><div>for N_s<=4, Ipopt can solve the problem. Otherwise, IPOPT gave the following message:</div><div><br></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 <a href="http://projects.coin-or.org/Ipopt">http://projects.coin-or.org/Ipopt</a></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>This is Ipopt version 3.8.0, running with linear solver mumps.</div>
<div><br></div><div>Number of nonzeros in equality constraint Jacobian...: 1743324</div><div>Number of nonzeros in inequality constraint Jacobian.: 225000</div><div>Number of nonzeros in Lagrangian Hessian.............: 540888</div>
<div><br></div><div>Exception of type: TOO_FEW_DOF in file "f:\stefan\nbBuildDir\Ipopt\releases-3.8.0\Ipopt\src\Interfaces\IpIpoptApplication.cpp" at line 788:</div><div> Exception message: status != TOO_FEW_DEGREES_OF_FREEDOM evaluated false: Too few degrees of freedom (rethrown)!</div>
<div><br></div><div>EXIT: Problem has too few degrees of freedom.</div><div><br></div></div><div><br></div><div>Is there anyway to avoid this problem?</div><div><br></div><div>Thank you very much for your kind attention.<br>
</div><div><br></div><div>I look forward for your favorable reply.</div><div><br></div><div><br></div><div>SIncerely Yours,</div><div><br></div><div>Novalio Daratha</div></div>