Re: [ublas] LAPACK Bindings HSEQR addition

From: Thomas Klimpel (Thomas.Klimpel_at_[hidden])
Date: 2008-05-30 16:25:29

Hello Jeremy,

> Can someone look at my attempt and either tell me to give up or how to proceed?

Have a look at hbev.hpp (and/or hees.hpp). The following construction is typically used to differentiate between the different types (e.g. double vs. complex<double>), because real versions just have one workspace argument, while complex versions have two workspace arguments.

    namespace detail {
       template <int N>
       struct Hbev{};

       /// Handling of workspace in the case of one workarray.
       template <>
       struct Hbev< 1 > {
       ...
       };
       /// Handling of workspace in the case of two workarrays.
       template <>
       struct Hbev< 2 > {
       ...
       };

       template <typename AB, typename Z, typename W, typename Work>
       int hbev( char const jobz, AB& ab, W& w, Z& z, Work work ) {
         ... 
         int info ;
         detail::Hbev< n_workspace_args<value_type>::value >() (jobz,
                       ...);
         return info ;
       } // hbev()

I have two other comments:

- please add a copyright line like
 * Copyright Jeremy Conlin 2008

- don't use "unsigned int" in lapack.h

Regards,
Thomas

-----Ursprüngliche Nachricht-----
Von: ublas-bounces_at_[hidden] im Auftrag von Jeremy Conlin
Gesendet: Fr 30.05.2008 21:48
An: ublas mailing list
Betreff: [ublas] LAPACK Bindings HSEQR addition
 
I have made a start with creating the bindings for the HSEQR functions for
LAPACK.  They are not complete; I was hoping someone could provide some
feedback and advice.  Currently I have implemented only one (double) of the
four (float, double, complex<float>, complex<double>) versions.  I have
tried to follow the example in the geev.hpp file for much of my work.
My current problem is trying to differentiate between the different types
(e.g. double vs. complex<double>).  I know this can be handled with
templates, but I'm not exactly sure how this should be taken care of.  Can
someone look at my attempt and either tell me to give up or how to proceed?

I have attached a diff file from my version to the current svn version as
well as my added hseqr.hpp file and a simple test main.

Thanks,
Jeremy Conlin