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MathGroup Archive 2006

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Re: OT: simplex method

  • To: mathgroup at smc.vnet.net
  • Subject: [mg66411] Re: [mg66352] OT: simplex method
  • From: "Chris Chiasson" <chris at chiasson.name>
  • Date: Thu, 11 May 2006 02:17:09 -0400 (EDT)
  • References: <200605101034.GAA21886@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

someone gave me the appropriate hint in another group

http://groups.google.com/group/sci.math.num-analysis/browse_thread/thread/9e9f59f48fa78398

On 5/10/06, Chris Chiasson <chris at chiasson.name> wrote:
> Hello MathGroup,
> This is more of a numerical methods question than a Mathematica
> question. Please forgive the off topic post. I just feel that you are
> mathematically knowledgeable people and might be inclined to provide
> instructive input.
>
> First, this is a homework problem, so if you don't want to help me
> with homework - uh... forget what I just told you and continue
> reading.
>
> Here is a Linear Programming problem I am trying to solve:
>
> eq=And[F==2*X[1]+4*X[2],2*X[1]+X[2]>=2,X[1]>=0,X[2]>=0]
>
> Asking Mathematica for the answer (minimum of F) is trivial.
>
> Minimize[{Last@First@eq,Rest@eq},List@@eq[[{-2,-1},1]]]
>
> If I want to solve it via the simplex method, here is the tableau
>
> {{2,1,-1,2},{2,4,0,F}}
>
> The only problem is, I can't see where I would be able to create a
> basis of two variables if I only have one constraint. I have solved
> all the other linear programming problems thrown at me so far, but
> this one leaves me scratching my head. I have tried augmenting the
> tableau with extra variables and also tried expressing the X[1]>0,
> X[2]>0 constraints in the tableau, but both avenues didn't yield an
> answer.
>
> Could someone please explain what is happening in this problem and how
> one should apply the simplex method in this case?
>
> Thank you,
> --
> http://chris.chiasson.name/
>
>


--
http://chris.chiasson.name/


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