[Coin-lpsolver] Presolve removed variable's values?

[Sathi]

John,

Thanks !

> For some types of variables, the removed variables will be fixed at 
> their bounds - but there is no easy way to find out which bound.  For 
> presolve operations which get rid of constraints like x + 5y = 7 then 
> these values are only known during postsolve.  In your case most of 
> the operations are probably the result of constraints like x + 2y +3z 
> <= 0 in which case they would be fixed to lower bound.
>

All the variables in the model  just have >=0 bound, so I think all the 
removed variables will be fixed at zero during the postsolve process. I 
will check this out first.

Sathi









> >
> > I am at present looking at presolve literature and also the COIN 
> presolve
> > codes to figure out these issues. Any help would be useful to me.
> >
> > Thanks,
> > Sathi
> >
> > ___________________________________________________________________
> > [attachment "presolve_stats.txt" deleted by John J Forrest/Watson/IBM]
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