Re: Eigenvalues to find roots of polynomials

[Ada novice <yogeshwarsing@gmx.com>]

On Jul 25, 9:22 pm, Simon Wright <si...@pushface.org> wrote:
> marius63 <amado.al...@gmail.com> writes:
>
> [...]
>
> Seehttp://sourceforge.net/projects/gnat-math-extn/for work I did
> supporting asymmetric real and non-hermitian complex matrices.

Thanks Simon for making this possible. I have been away from Ada for a
few months. Last week I looked at your codes and tested them for a few
cases. The codes worked fine :) as expected. In structural dynamics,
one can have three matrices to deal with. These three matrices are
combined with each other to form then the matrix A and B that you have
in your codes and hence it is a generalized eigenproblem. But the
eigenvalues are obtained in conjugate pairs as we are dealing with
double-sized matrices. I am waiting for a book to arrive here and then
I will formulate and use your Ada codes. For such a problem, I have my
codes in Matlab to compare with.

A very useful theorem that I learned several years back is the
Gershgorin Theorem. It lets you know the bounds for your eigenvalues.
More information here:

http://en.wikipedia.org/wiki/Gershgorin_circle_theorem


Cheers
YC