[Ipopt] infeasible starting point

[Chunhua Men]

Hi,

I am new to IPOPT. I need to solve a constrained NLP problem, but I don't
have a feasible initial solution.

IPOPT ran a very long time (I set the max iteration as 20,000) and could
not find a feasible solution (the "inf_pr" is still around 1000 after
20,000 iterations).

Then I changed "start _with_resto" to "yes", then within 20000 iterations,
still no feasible solution found.

My model is not very big (~2000 decision variables with ~10 constraints).


My question are:
1) Do I have to provide a feasible solution as the starting point?
2)  how does IPOPT judge a model  feasible or not?

Thanks!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.coin-or.org/pipermail/ipopt/attachments/20130730/519b34f9/attachment.html>