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Re: [Help-glpk] More conditional variables fun
From: |
Michael Hennebry |
Subject: |
Re: [Help-glpk] More conditional variables fun |
Date: |
Tue, 13 Oct 2009 07:12:10 +0400 |
This might bounce from the mailing list.
NDSU has been mucking with my return address.
On Mon, 12 Oct 2009, Yaron Kretchmer wrote:
> Now I'd like to be able to model conditional non-binary variables. Does
> anybody know how to formulate this in mathprog?
>
> ----------Begin Description -------------------
> *) a,b are binary
> *) c,d,e is continuous.
> *) I'd like c to be
> - 0 if a=b=0
> - d if a=0,b=1
> - e if a=1,b=0
> - 0 if a=b=1
> ----------End Description
You can't do this without a discrete variable.
Projecting onto the real coordinates, the feasible set is
{(c,d,e) in R**3 such that c in {d,e,0}}.
It is the union of the convex sets, not one or two.
One binary variable will not be enough.
One ternary variable might be, but I doubt it.
--
Michael address@hidden
"Pessimist: The glass is half empty.
Optimist: The glass is half full.
Engineer: The glass is twice as big as it needs to be."
RE: [Help-glpk] More conditional variables fun, D'Agostino, Larry - TX, 2009/10/12
Re: [Help-glpk] More conditional variables fun, Andrew Makhorin, 2009/10/13
Re: [Help-glpk] More conditional variables fun, Andrew Makhorin, 2009/10/13
- Re: [Help-glpk] More conditional variables fun,
Michael Hennebry <=
- Re: [Help-glpk] More conditional variables fun, Michael Hennebry, 2009/10/12
- Re: [Help-glpk] More conditional variables fun, Michael Hennebry, 2009/10/13
- Re: [Help-glpk] More conditional variables fun, Michael Hennebry, 2009/10/14
- Re: [Help-glpk] More conditional variables fun, Alexander Schnell, 2009/10/14
- Re: [Help-glpk] More conditional variables fun, Michael Hennebry, 2009/10/14