Originally posted by: Uonly

Iteration log . . .
Iteration:     1   Dual objective     =        794618.792788
Iteration:    38   Dual infeasibility =             0.000042
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788
Iteration:    47   Dual objective     =        794618.792788

It is clear that it is doing some pricing and pivoting, but why the iteration number is the same?

Thanks

Originally posted by: RWunderling

This looks indeed strange - I don't recall ever seeing this before.  Could you please PM me a sav file of the model and detailed instructions on how to reproduce this behaviour (including port, version, parameter settings)?

Thanks,

Roland

Originally posted by: T_O

My first guess was that it is doing some "mini-iterations" of the bound flipping ratio test, but of course, I do not know the implementation details in CPLEX. Maybe, it is something completely different.

Originally posted by: Uonly

Yes I was wondering why. I am too bold to suspect that could be "bug" in cplex. when I was setting the SIMDISPLAY to be 2. I can observe many iteratoins of price in and out when the iterations number is 47.

Btw, would you please provide your email address so that I can send you the code and explain how to repeat the issue?

Thanks again Roland.!

Originally posted by: RWunderling

Please PM to roland<dot>wunderling<at>at<dot>ibm<dot>com (no typo with the <at>at).
Thanks,
Roland

Originally posted by: RWunderling

Thanks for providing the sample.  This is indeed a minor bug, whereby the iteration count is not increased when dual superbasic variables are pivoted out of the basis.  It will be fixed in the next release.