[Ipopt] What shall I do when "Not enough memory" is encountered

[Andreas Waechter]

Hi Weifeng,

Please send emails regarding Ipopt to the Ipopt mailing list.

As for your question, you might want to play with the options

# ma27_liw_init_factor:
# ma27_la_init_factor:
# ma27_meminc_factor:

Also, choosing smaller pivot tolerances might help (the default is rather 
small already though).  Furthermore, making sure that your problem is 
well-scaled and well-posed will probably reduce the fill-in in the linear 
solver.

Regards,

Andreas

On Thu, 1 Apr 2010, Weifeng Chen wrote:

> Hi Andreas,
>
> I am a doctoral student of Department of Control Science and Engineering of
> Zhejiang University.
>
> Recently, I used IPOPT (Version 3.8.1) compiled with MS VS 2008 to solve a
> large-scale optimization problem which was establish with Aspen Plus.
> Unfortunately, IPOPT exited with a message, "Not enough memory". The linear
> solver utilized was MA27 and the second derivative information was
> approximated by means of BFGS. How shall I handle this problem? Looking
> forward to your reply! Thank you very much!
>
> Information on the optimization problem
> Number of variables:
> 106375
> Number of equality constraints:                                    106374
> Number of non-zero elements in constraint Jacobian:     1492803
>
> The computation was carried out on the machine SONY VGN-SR58 running Windows
> XP and with Intel(R) Core (TM) 2 Duo CPU P8800 and 4.0G RAM memory.
>
> Best regards,
>
> Weifeng Chen
> Department of Control Science and Engineering
> Zhejiang University, Hangzhou 310027
> People's Republic of China
>