[Ipopt-tickets] [Ipopt] #296: MUMPS solver problems

[Ipopt]

#296: MUMPS solver problems
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  Reporter:  marco.giuntoli  |      Owner:  ipopt-team
      Type:  defect          |     Status:  new
  Priority:  normal          |  Component:  Ipopt
   Version:  3.11            |   Severity:  normal
Resolution:                  |   Keywords:
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Comment (by marco.giuntoli):

 Dear,
 thanks for your answer. Basically, this is the pseudo code:

 -preparing object function (and its gradient);
 -preparing constraints function;
 -preparing jacobian function;
 -preparing x0;

 for (1...N)
    - Starting memory for IPOPT
    - CreateIpoptProblem(...)
    - pass x=x0
    - IpoptSolve(x)
    - get x
    - FreeIpoptProblem()
 end

 At each iteration have a different result (the differents starting after
 the 8th digit) and the interations can be different (from 15 iterations to
 45 iterations). I'm using vs2017 with IpOpt-vc10.dll: I think that this
 can be the problem. I need to use the same compiler.

 Any suggestions?
 Thanks a lot.

 Marco


 Replying to [comment:1 stefan]:
 > But you are running Ipopt on different problem instances here, right?
 Then it can (or should) happen that the solution process differs, of
 course. It is not so nice if the performance of Ipopt changes a lot due
 when there are only small changes in the problem instance, but I wouldn't
 know what to do about this.

--
Ticket URL: <https://projects.coin-or.org/Ipopt/ticket/296#comment:2>
Ipopt <http://projects.coin-or.org/Ipopt>
Interior-point optimizer for nonlinear programs.