[SCIP] Dual solution =0.0

[Ambros Gleixner]

Dear Lahcene,

This is complicated.  The method SCIPgetDualsolLinear() only returns 
something meaningful when used within a SCIP plugin for a constraint of 
the transformed problem, e.g., in a pricer plugin.  The method will 
always return 0 for constraints of the original problem.

When you use SCIP externally, you are right that one condition is to 
turn off presolving.  Then you can look at the method 
SCIPgetDualSolVal().  But also this is only available, when the problem 
is an LP and you are in SCIP_STAGE_SOLVED.

Best,
Ambros




Am 05.07.2018 um 18:57 schrieb lahcene mezouari:
> Hi;
> In my algorithm i need dual value but when i use "SCIPgetDualsolLinear " 
> the result is always "0.00".
> thanks in advance !
> 
> 
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-- 
Ambros Gleixner, Research Group Mathematical Optimization Methods at 
Zuse Institute Berlin, http://www.zib.de/gleixner