       Help with minimization of Eigenvalues

• To: mathgroup at smc.vnet.net
• Subject: [mg87747] Help with minimization of Eigenvalues
• From: Chimico <Dario.Bressanini at gmail.com>
• Date: Wed, 16 Apr 2008 06:50:22 -0400 (EDT)

```Hi,

I am trying to minimize a particular eigenvalue of a generalized
eigenvalue problem that depends on a few parameters. I have the
following problem:

Suppose we have two matrices s and m like these (the real matrices are
much more complicated)

m = {{a, b}, {b, -a + 1}}

s = {{1, 0}, {0, 3a}}

If I define the function Eig

Eig[a_, b_] := Eigenvalues[{m, s}]//First

And use it with the FindMinimum function it does not work.
Infact just calling

Eig[1,2] gives the error

Eigenvalues::gfargs:
Generalized Eigenvalues
arguments accept only matrices with machine real
and complex elements. More...

Even inserting Evaluate[] into the Eigenvalues function does not work.
What am I doing wrong?
Any help would be appreciated :-)
thanks  Dario

```

• Prev by Date: Re: How to solve this simple equation?
• Next by Date: Re: List re-arrangement question
• Previous by thread: Re: pdf and accents - SOLUTION FROM MYSELF
• Next by thread: Re: Help with minimization of Eigenvalues