Re: Eigenvalue Problem
- To: mathgroup at smc.vnet.net
- Subject: [mg16942] Re: Eigenvalue Problem
- From: Pierre infelta <pierre.infelta at epfl.ch>
- Date: Thu, 8 Apr 1999 02:32:43 -0400
- Organization: EPFL
- References: <7e9odu$3km@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
try
Needs["Miscellaneous`RealOnly`"]
m = {{10 A, 0, B, 0, 0, 0},
{0, -2 A, 0, C, 0, 0},
{B, 0, -8 A, 0, C, 0},
{0, C, 0, -8 A, 0, B},
{0, 0, C, 0, -2 A, 0},
{0, 0, 0, B, 0, 10 A}}
The answer replaces the nonreal roots by nonreal.
Peter Huesser wrote:
>
> Hello everybody
>
> I am trying to solve the eigenvalue problem for the following matrix:
>
> m = {{10 A, 0, B, 0, 0, 0},
> {0, -2 A, 0, C, 0, 0},
> {B, 0, -8 A, 0, C, 0},
> {0, C, 0, -8 A, 0, B},
> {0, 0, C, 0, -2 A, 0},
> {0, 0, 0, B, 0, 10 A}}
>
> which is symmetric. Now mathematica returns some complex eigenvalues
> which is not
> possible for a real, symmetric matrix. Can anybody help me ? Maybe the
> error occurs because
> mathematica means that the coefficients are complex but how can I make
> them real ?
>
> Thank's in advance for any help.
>
> Peter Huesser