Re: [Lapackpp-devel] Symmetric (packed) matrices

[Dominik W. <dom...@ar...>]

>> Do you know why LaSymmMatDouble needs two arguments in the constructor?
>> Unfortunately it's not even checked if they are the same, I mean "assert
>> ( m ==n );" ...

> Interesting :-) . No, I don't know. In the current form this is
> obviously wrong. The LaSymmMatDouble matrix, as well as the
> LowerTriangBlaBlaBla matrix, should have a one-argument constructor each.

I agree. At this time someone can allocate a "symmetric" matrix with
dimension 10x100 if he likes to do. I do not know what the result is if
you call a Lapack-function with it...

I don't use symmetric matrices that much so I do not know why it's
"derived" from a triangular matrix and why it uses two dimension. Maybe
I have time to review the code at my holidays at end of december.

> However, currently lapackpp doesn't use the "packed storage" matrix
> format at all. [...] You can now either add the packed storage with its
> related solver functions as an additional set of classes and functions
> (LaPSymmMatDouble, for example).

As I said above I do not use symmetric matrices and I do not know much
about the storage scheme for Lapack. So I'm afraid I won't be a help here...

> Or we can decide to switch the existing
> symmetric classes over to packed storage. Unfortunately I have no idea
> whether anyone relies on the existing symmetric classes.

Hm, good question. As in lapackpp-classes you have no choice to directly
access the "dead" part of the memory. So it may be no difference if we
change it to packed storage. But as you point out, not all
Lapack-functions are implemented for packed storange so a new class
would be much better.

Greetings, Dee