Problems returning dual variables ?

[pedroborgesmelo]

Hey Guys!

I have problems here taking the dual variables when using CbcSolver()
When I use ClpSolver(), everything goes fine..

Do we have a problem with CbcSolver?

Thanks,

[joehuchette]

The duals for linear optimization (Clp) and integer optimization (Cbc) are quite different, and so Cbc doesn't return any dual information (besides bounds on the objective function).

[pedroborgesmelo]

Hey Joey! Thanks. I thought Cbc would work as a linear solver in the absence of integer variables.. Best, 2018-01-11 11:56 GMT-02:00 Joey Huchette <notifications@github.com>:

…

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-- Pedro Henrique Borges de Melo

[joehuchette]

It will, but it still won't provide dual information. If you're certain your problem is an LP, you should just pass it to Clp instead.

[mlubin]

It's possible that duals are actually provided through the CBC C API, but we haven't hooked them up if they are.

[joehuchette]

I gave it a cursory look before and didn’t see anything, but I could’ve missed it.

…

On Thu, Jan 11, 2018 at 7:49 PM Miles Lubin ***@***.***> wrote: It's possible that duals are actually provided through the CBC C API, but we haven't hooked them up if they are. — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#50 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABTzUtHCI7gz0uywdunTcVF4LDxJeODCks5tJqwmgaJpZM4Ra2aB> .