[Coin-discuss] problems with OSL on Red Hat [was: AAP_BP example]

[Laszlo Ladanyi]

I have fixed OsiOslSolverInterface::getDualRays(). Basically (as Matt noticed)
the returned vector vas the negative of the real dual rays. It should work
properly now.

--Laci

On Tue, 2 Dec 2003, Stephan Hennig wrote:

> Matthew Galati schrieb:
> 
> > [...]
> > Adding a sanity check "isProof" should show that the return from OsiOsl's
> > getDualRays returns a ray that is not a certificate. In my check I am using
> > the following definition:
> > 
> >      p is a proof iff
> >      Let z_j = u_j where p' A_j > 0
> >              = l_j where p' A_j < 0
> >      p'b - p'Az > 0
> > 
> > Using the (negative) of the return of OsiClp::getDualRays works fine. 
> > Using the current return (or its negative) of OsiOsl and OsiCpx does not 
> > provide a proof. Using the return of CPXdualfarkas also works fine - but 
> > this is not currently implemented in OsiCpx. I might be implementing 
> > something wrong - but that is my guess. For anyone that is interested, I 
> > have some test cases where the isProof(OsiOsl/Cpx::getDualRays) = false.
> > [...]
> 
> I think I got it. The wrong solution value on some problem instances and the
> segfault are two independent issues. Because they appeared to me at once I
> didn't separate them.
> 
> The segfault issue can be worked around by the two alternatives Laszlo posted.
> The second still endures (and you accidentally discovered the same problem
> with CPLEX yesterday). When I now read the other thread I must admit you
> already stated that before.
> 
> Regards,
> Stephan Hennig
> 
> 
> 
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