[Cbc] Antw: Re: Cut efficiency in cbcSolve for versions 2.0.0, 2.1.0, 2.2.2and 2.3.0

[Torsten Fahle]

Haroldo,

> Did you get the integer optimal solution with all versions ?
> I'm just thinking that perhaps the better bounds of previous versions could
> include inequalities which could cut integer optimal solutions - these
> issues perhaps are fixed in newest releases....

This could be the case. However, solution values found by  
* CBC 2.0.0 with probing on and no other cuts  (246.295513999) 
* CBC 2.3.0 without any cuts (246.2995200001)
differ only slightly by less than 1e-5. This is probably in the area of internal epsilons
in the code, so it's hard to say from the outside whether some cuts removed an optimal solution
in the older code.
By the way: CPLEX 9 claims that 246.299514 is optimal, XPRESS 2008 stops at 246.299524.
Thus, it's hard to say which result is really better and which one is due to numerical issues.

Torsten