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<DIV>You know more about your model than I do, and I’ve never used APMonitor for
modeling. You may want to ask there. The fact that it says your model has
negative 2 degrees of freedom sounds bad though. If random initial guesses are
giving the “Problem may be infeasible” exit message, then again it’s indicative
that finding a feasible point for your optimization problem is challenging. If
there are simpler calculations you can do to obtain a close-to-feasible solution
to start from (and I mean taking into account the structure and constraints of
your problem, something much more sophisticated than all zeros or a random
guess), you will likely need to do that to get reliable behavior on this
particular problem.</DIV>
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<DIV style="font-color: black"><B>From:</B> <A
title=mostafa.safdarnejad@gmail.com
href="mailto:mostafa.safdarnejad@gmail.com">Mostafa Safdarnejad</A> </DIV>
<DIV><B>Sent:</B> Saturday, July 19, 2014 3:21 PM</DIV>
<DIV><B>To:</B> <A title=kelman@berkeley.edu
href="mailto:kelman@berkeley.edu">Tony Kelman</A> </DIV>
<DIV><B>Cc:</B> <A title=ipopt@list.coin-or.org
href="mailto:ipopt@list.coin-or.org">ipopt</A> </DIV>
<DIV><B>Subject:</B> Re: [Ipopt] Fwd: help for restoration
failure</DIV></DIV></DIV>
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<DIV dir=ltr>Tony,
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<DIV>Thanks for your response. I am sure the problem is feasible because I have
other scenarios running perfectly fine. I changed some concepts of my model and
I got this infeasibility. Although the model is infeasible now, the trends that
variables are making are quite reasonable (however I am not sure how reliable
trends for an infeasible case can be). I am using zero for almost all of
the initial values (as other feasible scenarios) but using other random initial
values got me to " Converged to a point of local infeasibility. Problem may be
infeasible." but no restoration failed error at the end of the output (however
there is "r" next to the iteration number. The output of solver is attached. Do
you have any further insight on what is going on? </DIV>
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<DIV>Thanks</DIV></DIV>
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<DIV dir=ltr><I><FONT face="comic sans ms, sans-serif">Mostafa
Safdarnejad</FONT></I></DIV></DIV><BR><BR>
<DIV class=gmail_quote>On Sat, Jul 19, 2014 at 3:58 PM, Tony Kelman <SPAN
dir=ltr><<A href="mailto:kelman@berkeley.edu"
target=_blank>kelman@berkeley.edu</A>></SPAN> wrote:<BR>
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<DIV>Essentially this means Ipopt had difficulty obtaining a feasible point
for your problem. Are you sure your problem is feasible? Would it be possible
for you to calculate a better initial starting point for the
optimization?</DIV>
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<DIV> </DIV>
<DIV style="BACKGROUND: #f5f5f5">
<DIV><B>From:</B> <A title=mostafa.safdarnejad@gmail.com
href="mailto:mostafa.safdarnejad@gmail.com" target=_blank>Mostafa
Safdarnejad</A> </DIV>
<DIV><B>Sent:</B> Friday, July 18, 2014 11:55 AM</DIV>
<DIV><B>To:</B> <A title=ipopt@list.coin-or.org
href="mailto:ipopt@list.coin-or.org" target=_blank>ipopt@list.coin-or.org</A>
</DIV>
<DIV><B>Subject:</B> [Ipopt] Fwd: help for restoration
failure</DIV></DIV></DIV>
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<DIV dir=ltr>Hi, I am using IPOPT solver for a NLP optimization and I got an
infeasibility error due to restoration failure (attached file). I am not
familiar with programming in IPOPT. So, I would appreciate if anyone can help
me with specific details on how to fix it? I am using APMonitor modeling
language and Matlab as my interface to run.
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<DIV> </DIV>
<DIV>Thanks</DIV>
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<DIV> </DIV></DIV></DIV>
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