[Coin-ipopt] How to couple variables in Ipopt without reformulation

[Andreas Waechter]

Hi Danh,

Sorry, I just realized that nobody ever answered to your question.

> I need to modify my current optimization problem by posing some constraints 
> of coupling variables:
>
> max f(x)                         max f(x)
> s.t.                                s.t.
> c(x)=0                  =>    c(x)=0
> x_U <= x <= x_L           x_i =x_j  (still unknowns)
>                                                  i = 1,3,5 j=2,4,6 for 
> example
>                                     x_L <= x <= x_U
>
> Is there any way to express these additional equalities without reformulation 
> of the optimization problem?
>

No, you will have to modify your code that formulates the NLP.  You will 
have to add more (very simple) equality constraints.

Regards,

Andreas