[Coin-discuss] Problem with a Branch and Price and dual variables

[Jakob Puchinger]

hi,

I am trying to implement a column gerneration algorithm,
and had some problems with dual rays to restore feasibilty after
branching.
So I wanted to check if cplex and CLP a returning the same values, in
order to determine where my problem is. I turn presolve off for cplex,
and give hints to CLP to turn presolve and DualSimplex off.
The problem is that after the first iteration I allready get different
dual variables back so the prices for column generation are different.
I allready looked at the .mps files of the solvers: they are the same.

I would be very gratefull if somone could give me a hint how to solve
this.

thank you in advance!
best wishes
jakob


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Dipl.-Ing. Jakob Puchinger
Algorithms and Data Structures Group
Institute of Computer Graphics and Algorithms (E186)
Vienna University of Technology
Favoritenstraße 9-11, A-1040 Vienna, Austria
email: japu at ads.tuwien.ac.at
phone: +43(1)58801/18627
http://www.ads.tuwien.ac.at/
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