sci.op-research

Hi Paul!

I've found a symbolic package for the REDUCE system: SYMOPT. There is
technical report about it:

http://www.fmi.uni-passau.de/forschung/mip-berichte/MIP-0203.ps

However, I'm looking for a Maple or Mathematica package or, better, a
free system.

Best regards, Humberto.

On 11 mar, 12:02, Paul Rubin wrote:
> humberto.bortolo...@gmail.com wrote:
> > Greetings!
>
> > Is there a mathematical software that solves symbolically aparametric
> > linearprogram, like that one:
>
> > min x + y
> > subject to ax + y >=3D 4
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0bx + y >=3D 7
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0x >=3D 0, y >=3D0
>
> > That is, I would like to see the solution in terms of the coefficients
> > a and b:
>
> > (x*, y*) =3D (3/(a - b), (4a - 7b)/(a - b)) if 7/a <=3D 4/b
> > (x*, y*) =3D (7/a, 0), otherwise.
>
> > Thanks in advance,Humberto.
>
> I don't think so. =A0For a small example such as yours, you might get some=

> traction using a computer algebra package (Mathematica, Maple, ...) and
> breaking the problem into cases. =A0To use your example above, two of the
> four inequality constraints must be binding at the optimal solution.
> Hypothetically, you could solve all six combinations symbolically and
> get six candidate solutions. =A0Not all would be feasible, and among the
> feasible ones not all would be optimal, but you might be able to derive
> conditions on a and b such that if (a, b) satisfies ___ then ____ is the
> optimal solution. =A0Obviously, this approach would be useless for
> anything larger than trivial problems.
>
> /Paul- Ocultar texto entre aspas -
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