[Coin-ipopt] How to choose objective functions from multi-objective functions

[Andreas Waechter]

Hi Rui,

I think that we wrote the AMPL interface in Ipopt so that it complains (in 
the way you describe) when there are more than one objective functions in 
the model.   Maybe the trick that Michal mentioned already does the trick 
for you.

If not, please submit a ticket at the Ipopt trac page and attach the AMPL 
model that give you trouble.

Thanks,

Andreas

On Sun, 20 May 2007, Michal Kaut wrote:

> Hello,
>
> you can use named problems, using the "problem" keyword. This is one of the 
> new features of AMPL, so you won't find it in the first edition of the book.
> For a detailed description, including examples, see
> http://ampl.com/NEW/loop2.html
>
> Regards,
> Michal Kaut
>
>
> Rui Huang wrote:
>> Hello
>> 
>> I have two objective functions.
>> So I have two same ampl models, except that each one has a different 
>> objective function.
>> and try to solve them together without "reset"
>> But ampl breaks
>> "There is more than one objective function in the AMPL model, but 
>> AmplTNLP::set_active_objective has not been called",
>> 
>> I do not know how to call this function.
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