[AMPL 2563] FilMINT optimal solution really optimal?

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[AMPL 2563] FilMINT optimal solution really optimal?

by x-22 :: Rate this Message:

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When filMINT solver reports "Optimal solution found" does it really mean global optimal solution?

Does the solver assume convexity for all functions in the model? Where do we get such info about the solver?

For my model, the solver reports optimal solution. However, there are at least two variables that do not have optimal values. What I mean is, solver could have picked different values for these variables and have gotten lower values for the objective fuction (this being a minimization problem).

Thanks in advance!



     

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[AMPL 2564] Re: FilMINT optimal solution really optimal?

by Robert Fourer-2 :: Rate this Message:

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For answers to questions about FilMINT, see

   http://www.mcs.anl.gov/~leyffer/papers/fm.pdf

where it is stated,

   ... we focus on the case where the functions f and g_j are
   convex, so that by relaxing the restriction y in Z^p, a convex
   program is formed. The techniques we suggest may be applied
   as a heuristic in the case that one or more of the functions
   are nonconvex.

This suggests that FilMINT does not guarantee a global optimum when the
functions are not convex.  For more up-to-date information you can contact
the authors.

Bob Fourer
4er@...


> -----Original Message-----
> From: ampl@... [mailto:ampl@...]
> On Behalf Of x [to_rent_2000@...]
> Sent: Monday, June 01, 2009 9:25 PM
> To: ampl@...
> Subject: [AMPL 2563] FilMINT optimal solution really optimal?
>
>
> When filMINT solver reports "Optimal solution found" does it really mean
> global optimal solution?
>
> Does the solver assume convexity for all functions in the model? Where do
> we get such info about the solver?
>
> For my model, the solver reports optimal solution. However, there are at
> least two variables that do not have optimal values. What I mean is,
> solver could have picked different values for these variables and have
> gotten lower values for the objective function (this being a minimization
> problem).
>
> Thanks in advance!
>



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