Subject: Re: [ublas] Banded matrix storage
Date: 2013-08-01 17:37:05
No problem, just wanted to make sure that I don't do something wrong.
In case it makes sense :
>From a quick look, it seems to me that one should replace the packed storage with banded.
This is in accordance with netlib nomenclature, but I guess would break all shorts (mine included ;) )
---- Nasos Iliopoulos <nasos_i_at_[hidden]> wrote:
> To all:
> it would be of great help if at least another pair of eyes can review
> the code before it moves forward into an official release. Here is the
> github branch:
> modified test cases (added non square matrices):
> and modified banded.hpp:
> relevant lines are 25-56 and and anything that contains the
> "banded_indexing" specializations.
> One important change I made relatively to the old code is that I
> enabled range checking only in debug builds (where appropriate).
> Please also note that I didn't follow Gunter's suggestion on adding a
> new template argument, since I felt it would break backwards
> compatibility in certain cases.
> test instructions (not final but they should work):
> please do a git checkout ublas_bugfix0002_fix_banded_tc7549 prior to
> compiling with b2 otherwise you will be compiling the master branch.
> I will megre it into ublas_develop after 1-2months so that there is
> enough time for review and maybe apply some minor modifications I have
> in mind.
> On 08/01/2013 01:05 PM, pmamales_at_[hidden] wrote:
> > PS: Although I asked a very-related question, I did not see any answer, so I thought it was ignored as
> > trivial/already answered elsewhere. However, I did receive these very relevant emails. Am I doing something wrong ?
> Gunter had created some test cases and a bug report on boost trac, so I
> figured it would help the discussion more to answer to that thread. I
> restrained myself flooding the mailing list with responses, since yours
> was just around the corner.
> > ---- Rutger ter Borg <rutger_at_[hidden]> wrote:
> >> On 2013-07-31 17:22, Nasos Iliopoulos wrote:
> >>> Gunter,
> >>> I am working on this bug, but based on the test case I am wondering why
> >>> should the expected row-major data layout be:
> >>> 0, 0, 11, 12, 0, 21, 22, 23, 31, 32, 33, 34, 42, 43, 44, 45, 53, 54, 55, 0
> >>> And not
> >>> 0, 12, 23, 34, 45, 11, 22, 33, 44, 55, 21, 32, 43, 54, 0, 31, 42, 53, 0, 0 ?
> >>> For the moment I got the column-major implementation working as
> >>> expected, but I need to add some more tests cases to make sure it is
> >>> working for non-square matrices as well.
> >>> Regards,
> >>> -Nasos
> >> Hey Nasos,
> >> great work. The data in banded matrices is stored either row-by-row
> >> (row-major), or column-by-column (column-major). This is defined by
> >> netlib. AFAIK, a diagonal-by-diagonal storage scheme is not supported by
> >> CBLAS.
> >> Cheers,
> >> Rutger
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