[Lapackpp-devel] Re: matrix library help

[Christian S. <sti...@tu...>]

Am Freitag, 25. Februar 2005 19:19 schrieb Arun ramakrishnan:
> i have installed lapack++
> but i dont know how to turn on complex types.
> it says " Note: To switch on the support for complex-valued matrices,
> you need to define the macro LA_COMPLEX_SUPPORT in your application "

Add 
 #define LA_COMPLEX_SUPPORT
everywhere before you have the #include <lapackpp.h> or similar include 
directives.

> the non-trivial question is about a suitable library for my requirements.
> *calculating pseudoinverses for complex matrices

That's supported by lapack++ relatively well. The best way to do this is 
calculating the SVD of the matrix and using this for the pseudoinverse. 

> *calculating eigenvalues and their corresponding LEFT eigenvectors
> for a GENERALISED eigenvalue problem involving complex matrices.
> i require the final code to be compiled in gcc on a linux platform.
> it would be nice if you can tell me as to which of the following
> packages would suit my requirements.
> 1. lapack++

Lapack++ currently calculates eigenvalues only for symmetric real-valued 
matrices. It wouldn't be too difficult to add support for general 
(non-symmetric) eigenvalue calculation, both real and complex, since the 
underlying lapack (without the ++) already has many functions for this. 
However, I don't have time right now and also I don't have any test cases for 
this. If you intend to add this for yourself, you would have to be familiar 
how FORTRAN functions are called from a C program, but then it would be a job 
of 2-3 hours (so not too difficult). I would happily accept any program code 
and add it to future releases. 

> 2. MTL
> 3. PETSc and SLEPc

I don't know these packages. If they fulfil your requirement right away, then 
I'd suggest you should simply use them and not care any more about lapack+
+ :-)

Best regards,

Christian Stimming