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Subject: Re: [ublas] leading dimension for lapack bindings
From: petros (pmamales_at_[hidden])
Date: 2012-03-02 15:57:26

Thank you Thomas.
Please allow for a couple more questions.
Want to use the bindings with mkl. Can I ? I thought I saw people
on the web claiming they could - no problem, they said.
Assuming this to be the case, can I also do it for the 64-bit builds?
If I do not use CLAPACK does this mean that I use the fortran interface ?
I have been assured from intel that mkl and clapack have the same

The C API of mkl does not provide with the const qualifiers. Neither does
the CLAPACK.h - at least the
one I just checked upon in the web.
Can I hope that the const qualifiers I see in the bindings are a result of
some extra effort put
by the designers of the library (vary likely, some boost type "magic" ? ).
Btw, is there a way to overwrite the include <CLAPACK.h> ? (or just create
my dummy one, caling mkl.h ) ?

Finally, to answer your question, for mkl to work optimally and securely,
certain constraints on the
leading dimension need to be met - more than smple data allignment. This
forces me to define my matrix as
a range of a ublas matrix that I hold under the proverbial rug. Hence my
bind (no pun or maybe a little ;-))

Thank you very much for your help, which is invaluable given the scarcity of
Apologies for imposing on a Fri afternoon,
Best Regards,

-----Original Message-----
From: Thomas Klimpel
Sent: Friday, March 02, 2012 3:39 PM
To: ublas mailing list
Subject: Re: [ublas] leading dimension for lapack bindings

petros wrote:
> I want to use the gesv function of numeric bindings for a matrix_range
> (i.e. a submatrix).
> LAPACK expects this to be the number of rows (column_major layout) of the
> original matrix.
> Is the bindings library “smart” enough to figure it out ?

Of course it is smart enough.

> Alternatively, if I want to use the bindings calls with derivative classes
> of the boost
> matrix how can I overwrite this “standard” behavior (i.e. leading
> dimension)?

I get the impression that you ask how to write a binding for your own matrix
type. That's quite easy, but hopefully won't be required...

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