[Coin-discuss] Branch and price restore feasibility dual rays

[Jakob Puchinger]

hi,

I am looking again at my problem from february, where I cannot use the 
dual ray from OsiCpxSolverInterface to generate a variable breaking 
infeasiblity, whereas the ray from OsiClpSolverInterface works well.
Until now I used Clp which worked well,
but I would like  to compare to  cplex.

I am applying B&P to a 2D bin packing problem, each variable is 
a pattern, and each row corresponds to an item (it guarantees that the 
item is used). 
OsiClp returns a dual ray having one entry set to a high value, and the 
others to zero, it therefore gives me the index of a missing item of 
the solution (i.e. adding a pattern containing this item can restore 
the feasibility).
OsiCpx returns a dual ray having several entries set to 1, or 0.5, but
the entries correspond to items which are allready available in the 
solution, therefore I cannot generate a variable breaking infeasibility
using this information.

thank you for your answers (also for the answers from february)!

best wishes
jakob puchinger