[Ipopt-tickets] [Ipopt] #228: speed up function evaluation

[Ipopt]

#228: speed up function evaluation
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Reporter:  wan75          |      Owner:  ipopt-team
    Type:  clarification  |     Status:  new
Priority:  normal         |  Component:  Ipopt
 Version:  3.11           |   Severity:  normal
Keywords:                 |
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 I used IPOPT to solve a convex QP with linear constraint. I manage it with
 C++ interface and solution is correct but function evaluation is time
 consuming. It seems to me that evaluation of the hessian of the jacobian
 is espicially too long whereas it is constant for such type of problem.

 I try to define the column and row index and non zeros value in class
 variable in the get_nlp_info method of the interface and in eval_h i just
 copy in iRow, jRow and value variable. But it doesn t work, to have a
 correct solution i have to made a std::copy of my member pointer data
 my_col, my_row and my_value. I don't understand why and i do not save time
 with a memory copy.

 My first question: Is it a good way ta save time in fcntion evaluation, in
 particular for convex QP?
 My Second quastion: Why it need to perform a memory  copy from my pointer
 of the pointer of the interface

 I appreciate your help.

 Best regards,
 Erwan Jolivet
 Biomehcanical ingeneer.

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Ticket URL: <https://projects.coin-or.org/Ipopt/ticket/228>
Ipopt <http://projects.coin-or.org/Ipopt>
Interior-point optimizer for nonlinear programs.