Re: writing values of variables to log file every iteration

Be careful about the pre-processing that GLPK does.  If pre-processing is turned on (and that is the default) then the intermediate solutions may not be in the same form as the final solution.

From: Help-glpk [mailto:[email protected]] On Behalf Of Heinrich Schuchardt
Sent: Tuesday, November 14, 2017 9:31 AM
To: wilko heitkoetter; Help Glpk
Subject: Re: [Help-glpk] writing values of variables to log file every iteration

Hello Wilko,

you will need some programming.

If by iteration you refer to tbe branch and bound for MIPs implement a callback function.

If you refer to Simplex iterations you will have to modify the coding of the GLPK library.

Regards

Heinrich
--
Diese Nachricht wurde von meinem Android Mobiltelefon mit GMX Mail gesendet.
Am 14.11.17, 15:25, wilko heitkoetter <[email protected]<mailto:[email protected]>> schrieb:
Dear Developers,

I am a PhD student at University of Oldenburg (Germany). For troubleshooting, I would like GLPK to do the following, while solving an optimization problem:

For every iteration, the values that are assigned to the variables of the optimization problem at the respective iteration, shall be written to the log file.

Would this be possible? If yes, which option would I have to pass to the solver?


Already checked out the documentation and mailing list, but didnt find an answer.

I would be very grateful for an advise.


Best regards

Wilko Heitkoetter




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