[Ipopt] infeasible solution?

[Stefan Vigerske]

Hi,

maybe it would be better to create a ticket for this at
https://projects.coin-or.org/Ipopt/newticket

Then let your code run with print level 7, so you get more detailed 
output and attach that log (as text file, not a picture of the log, 
please) to the ticket.

If you have written your own code for derivatives, then I assume that 
you have tried the derivative checker already.

Stefan

On 06/23/2016 07:06 PM, Chunhua Men wrote:
> Hi Stefan, I just sent an attachment of the screenshot to you, but then I
> was told:
>
>
> Your mail to 'Ipopt' with the subject
>
>     Re: [Ipopt] infeasible solution?
>
> Is being held until the list moderator can review it for approval.
>
> The reason it is being held:
>
>     Message body is too big: 92768 bytes with a limit of 40 KB
>
> On Thu, Jun 23, 2016 at 10:02 AM, Stefan Vigerske <stefan at math.hu-berlin.de>
> wrote:
>
>> Hi,
>>
>> can you send the Ipopt log?
>> It's hard to believe that the constraint violation is exactly 0.
>>
>> I would think that it reports convergence to a point of local
>> infeasibility, if it gets to a point in which the constraint violation is
>> above the feasibility tolerance ("tol", in the simplest case) and it
>> doesn't see a direction in which it can reduce the infeasibility.
>> For a feasible convex NLP, this should not happen usually.
>>
>> Stefan
>>
>>
>> On 06/23/2016 05:37 PM, Chunhua Men wrote:
>>
>>> Hi, I used IPOPT to solve a convex NLP model. The starting point
>>> (initial solution) is feasible, but after <100 iterations, IPOPT always
>>> reports:
>>>
>>> "EXIT: Converged to a point of local infeasibility. Problem may be
>>> infeasible”.
>>>
>>> I printed out the final solution: each decision variable is within the
>>> bounds, and all constraints are met.  From the black console, IPOPT also
>>> reports "Constraint violation" is zero.  So, it is a feasible solution
>>> (though
>>> may not be optimal).
>>>
>>> May I know in which situation, IPOPT would report "Converged to a point of
>>> local infeasibility"?
>>>
>>> My IPOPT version is 3.11.9.9 and it was built in VS 2012 (64-bit) - Win7.
>>>
>>> Thanks! Chunhua
>>>
>>>
>>>
>>> _______________________________________________
>>> Ipopt mailing list
>>> Ipopt at list.coin-or.org
>>> http://list.coin-or.org/mailman/listinfo/ipopt
>>>
>>>
>>
>> --
>> http://www.gams.com/~stefan
>>
>


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