Re: [Vxl-maintainers] complex squareroot?

[Peter Vanroose <peter_vanroose@ya...>]

Martin,

I've now also added zgees and ztrsen to netlib.
This way, you can add your code unmodified to vnl/algo.

--	Peter.


Martin Reuter wrote:
I was interested in a complex Schur of a single matrix (zgees, I also
need ztrsen for reordering afterward). 

Do you think it makes sense to base that on the generalized case
(probably possible by passing the identity matrix for B?). I think it
might be better to wrap around zgees directly (that's what I did). 

About the matlab code, of course the original code is 
%   Copyright 1984-2005 The MathWorks, Inc.
(e.g. "type expm"  or "type sqrtm").

but it is rather simple code and I rewrote it in c++. Not sure if it
still falls under the copyright? How different does a re-write need to
be?









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Re: [Vxl-maintainers] complex squareroot?

[Martin Reuter <reuter@MIT.EDU>]

Thanks Peter,

I was interested in a complex Schur of a single matrix (zgees, I also
need ztrsen for reordering afterward). 

Do you think it makes sense to base that on the generalized case
(probably possible by passing the identity matrix for B?). I think it
might be better to wrap around zgees directly (that's what I did). 

About the matlab code, of course the original code is 
%   Copyright 1984-2005 The MathWorks, Inc.
(e.g. "type expm"  or "type sqrtm").

but it is rather simple code and I rewrote it in c++. Not sure if it
still falls under the copyright? How different does a re-write need to
be?

Thanks, Martin

On Mon, 2011-01-10 at 18:55 +0000, Peter Vanroose wrote:
> Martin,
> 
> I've just added to vxl netlib the necessary lapack files (zgges and its depencencies) for complex Schur.
> I've also added a (first attempt of) C++ interface in the new
>     core/vnl/algo/vnl_complex_generalized_schur.cxx
> which is essentially a complexified version of
>     core/vnl/algo/vnl_generalized_schur.cxx
> 
> Please verify whether this is what you need, and possibly modify or add to what I've committed to SVN. Not tested it thoroughly (but put a minimal test in core/vnl/algo/tests/test_complex_algo.cxx; please extend this).
> 
> Concerning your question on incorporating matlab licensed code into vxl: I've no idea about (and no experience with) this.  Maybe someone else on the list can comment on this issue?
> 
> Best regards,
> 
> --	Peter.
> 
> 
> On 2011-01-04 Martin Reuter wrote:
> > I wrote a complex Schur (I am not interested in the eigenproblem, just
> > the decomposition of a complex matrix, so I wrote a wrapper around zgees
> > from LAPACK, also the reordering ztrsen). I could not find those in the
> > netlib that comes with VXL. Currently these are just stand alone
> > routines that use vnl matrices, but it is not in the form of a vnl
> > class.
> > 
> > How can I contribute that code? Also I wrote stuff that might be of
> > interest (based on matlab code) to compute:
> > 
> > - sqrt of a matrix (using the Schur decomposition, see matlab sqrtm)
> > - exp of a matrix (see matlab expm)
> > - log of a matrix (also based on Schur and more, see matlab funm)
> > - pow of a matrix (using log and exp)
> > 
> > Can this be incorporated into vnl (expecially what I ported from matlab,
> > license)?
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> --
> 
> 

Re: [Vxl-maintainers] complex squareroot?

[Peter Vanroose <peter_vanroose@ya...>]

Martin,

I've just added to vxl netlib the necessary lapack files (zgges and its depencencies) for complex Schur.
I've also added a (first attempt of) C++ interface in the new
    core/vnl/algo/vnl_complex_generalized_schur.cxx
which is essentially a complexified version of
    core/vnl/algo/vnl_generalized_schur.cxx

Please verify whether this is what you need, and possibly modify or add to what I've committed to SVN. Not tested it thoroughly (but put a minimal test in core/vnl/algo/tests/test_complex_algo.cxx; please extend this).

Concerning your question on incorporating matlab licensed code into vxl: I've no idea about (and no experience with) this.  Maybe someone else on the list can comment on this issue?

Best regards,

--	Peter.


On 2011-01-04 Martin Reuter wrote:
> I wrote a complex Schur (I am not interested in the eigenproblem, just
> the decomposition of a complex matrix, so I wrote a wrapper around zgees
> from LAPACK, also the reordering ztrsen). I could not find those in the
> netlib that comes with VXL. Currently these are just stand alone
> routines that use vnl matrices, but it is not in the form of a vnl
> class.
> 
> How can I contribute that code? Also I wrote stuff that might be of
> interest (based on matlab code) to compute:
> 
> - sqrt of a matrix (using the Schur decomposition, see matlab sqrtm)
> - exp of a matrix (see matlab expm)
> - log of a matrix (also based on Schur and more, see matlab funm)
> - pow of a matrix (using log and exp)
> 
> Can this be incorporated into vnl (expecially what I ported from matlab,
> license)?










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