[Ipopt] Cutting back alpha due to evaluation error
andreasw at watson.ibm.com
Thu Jun 9 13:21:01 EDT 2011
It seems you are using GAMS. If you however also have an AMPL model, you
can set the option
from within AMPL (ipopt_options... it will not work from ipopt.opt). Then
AMPL will stop in case of an evaluation error and tell you which
constraint is causing the trouble.
On Wed, 8 Jun 2011, Martin Schmidt wrote:
> I have an NLP for which I often get the message
> "Warning: Cutting back alpha due to evaluation error".
> I know that this has something to do with constraints that are not well
> defined at the current point (like sqrt of negative numbers etc.).
> Is there any chance to analyze at which constraint in the model the
> problems occurs? I thought I could find some "inf" or "nan" values in
> the higher output levels but I didn't find anything.
> Thanks in advance,
> Ipopt mailing list
> Ipopt at list.coin-or.org
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