Re: Banded matrix storage

Nasos Iliopoulos <[email protected]>
Newsgroups gmane.comp.lib.boost.ublas
Message-ID <[email protected]>
Gunter,
  I implemented both your thinking (to my understanding) and mine. I 
think that yours reflects the symmetry of indexing (i.e. a row by row 
banded matrix is stored row by row, while a column-by column is stored 
column by column) while my original thinking doesn't  (i.e. a column by 
column  banded matrix as per netlib is either stored in a  row-major or 
a column-major container (as per the template argument).

I got both implementations running but I think I prefer your idea after 
all. I will apply the patch after the transition to github is complete.

-Nasos

> 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
>
>
>
> On 10/21/2012 04:57 PM, Gunter Winkler wrote:
>> Hello,
>>
>> Am Monday 15 October 2012 schrieb Rutger ter Borg:
>>> On 2012-10-15 18:09, Gunter Winkler wrote:
>>>> Could you please provide a simple test program which checks the
>>>> storage format? Then we (or maybe you) can create a new ticket.
>>>>
>>>> mfg
>>>> Gunter
>>> thanks for the response. I've attached a test program, its output is
>>> shown below. I haven't created a ticket yet, because I would like to
>>> make sure the test is correct first. I double-checked the 'expected
>>> data()' values, to me they seem to be correct.
>> I agree, the mapping from (i,j) to storage location is weird. I created
>> an issue:https://svn.boost.org/trac/boost/ticket/7549
>>
>> Now we only need a volunteer to fix it ...
>>
>> mfg
>> Gunter
>>
>>
>>
>> _______________________________________________
>> ublas mailing list
>> [email protected]
>> http://lists.boost.org/mailman/listinfo.cgi/ublas
>> Sent to:[email protected]
>
>
>
> _______________________________________________
> ublas mailing list
> [email protected]
> http://lists.boost.org/mailman/listinfo.cgi/ublas
> Sent to: [email protected]
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.