Re: ublas: hermitean matrices

From: jhrwalter (walter_at_[hidden])
Date: 2001-12-06 03:37:14

--- In boost_at_y..., Peter Schmitteckert (boost) <boost_at_s...> wrote:
> Salut,
> 
> >
> > That is conceivable. Do these border cases justify the 
introduction
> > of a new feature? We then would have to invent something I'd like 
to
> > call return type deduction,  i.e. implement and use a couple of
> > traits classes, which describe for example, that the product of a
> > hermitean with a real (or a complex with zero imaginary part?) is 
a
> > hermitean and the product of a hermitean with a complex (with 
nonzero
> > imaginary part?) is a general matrix (not to forget the 
corresponding
> > promotion rules).
> 
> I would vote for it, but I agree that a proper design is non 
trivial.
 
Ok.

> I'm planning to adapt my sparse matrix diagonalization routine
> for hermitean matrices to ublas. There I've implemented the Davidson
> algorithm, which needs in addition to the scalar product of the 
hermitean 
> matrix with a vector, the diagonal elements of the hermitean matrix.
> Since the eigenvalues of the hermitean matrix are real, a generic 
> implementation is cleaner using this feature.

I'm curious. If you encounter any problems, please let us know.
 
Regards
 
Joerg