[Scip] More solutions

[Julio Rojas]

Maybe I'm doing something wrong. Let me write the commands I'm issuing:

read problem.lp
set limits solutions 1
optimize
write solution sol1.txt
read problem.lp
set limits solution 2
optimize
write solution sol2.txt

sol1.txt and sol2.txt should be different, as the optimizer is telling me it
have found two solutions, but that's not the case as both solutions are the
same (diff sol1.txt sol2.txt).

If I do this:

read problem.lp
set limits solutions 1
optimize
write solution sol1.txt
set limits solution 2
optimize

Then the solver tells me the model is already solved and the same solution
appears.

So, maybe there is just one solution even if the solver says there are two?
Or I'm not doing the correct procedure to get the second solution.

Thank you so much for your time and patience.
-------------------------------------------------
Julio Rojas
jcredberry at gmail.com


On Thu, Nov 19, 2009 at 2:45 PM, Stefan Vigerske
<stefan at math.hu-berlin.de>wrote:

> Hi,
>
> I think the idea was to set the limit to one before starting
> optimization. Then it should stop when the limit is reached, and so on...
>
> Stefan
>
> Am 19.11.2009 14:22, schrieb Julio Rojas:
> > I tried to do what you suggest me. In one problem, after optimization,
> the
> > report is the following:
> >
> > SCIP Status        : problem is solved [optimal solution found]
> > Solving Time (sec) : 0.07
> > Solving Nodes      : 1
> > Primal Bound       : +5.20000000000000e+01 (2 solutions)
> > Dual Bound         : +5.20000000000000e+01
> > Gap                : 0.00 %
> >
> > So, in theory, I have two solutions. If I check the value of the solution
> > limit it shows:
> > SCIP> set limits solution
> > current value: -1, new value [-1,2147483647]: 2
> > parameter <limits/solutions> set to 2
> >
> > It doesn't matter if I do it before or after optimization, when I run
> > optimize again it tells me the problem has already been solved and no new
> > solution is presented.
> >
> > Thanks for your kind help.
> > -------------------------------------------------
> > Julio Rojas
> > jcredberry at gmail.com
> >
> >
> >
> >
> > _______________________________________________
> > Scip mailing list
> > Scip at zib.de
> > http://listserv.zib.de/mailman/listinfo/scip
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://listserv.zib.de/mailman/private/scip/attachments/20091119/653efb01/attachment.html