Re: improved QR & Cholesky updating

[Jaroslav Hajek]

On Wed, Jan 21, 2009 at 8:58 PM, John W. Eaton <address@hidden> wrote:
> On 21-Jan-2009, Jaroslav Hajek wrote:
>
> | Not really missing. What I meant is that after I fix this issue,
> | without qrupdate the functions will be present but sub-optimal. Maybe
> | some code will want to detect the situation. Now that I think of it,
> | how does "testif" detect that HAVE_QRUPDATE has been defined? Can this
> | be done directly from an m-file? If yes, then the above last argument
> | is dead...
>
> It's a bit of a kluge:
>
>  if (isempty (findstr (octave_config_info ("DEFS"), __feat{1}{1})))
>
> For "testif HAVE_QRUPDATE", __feat{1}{1} would be HAVE_QRUPDATE.
>
> If you think this would be a useful thing to be able to check for
> generally, then I think we should have a separate function for this,
> and maybe make it work more reliably than just using findstr on the
> value returned by octave_config_info ("DEFS").
>
> I can see where some feature checks like this might be useful, but I
> still think it would be best to avoid having very many checks of this
> kind in the Octave sources if possible.
>
> | OK. I originally considered rebasing QR & CHOL classes on a common
> | templated ancestor, but eventually I realized there was really not
> | that much code to share, as most methods are relatively thin wrappers
> | for the Fortran ones.
> | Still I can write a .cc file containing the replacement templates and
> | use that even in the current code.
>
> OK.
>
> Thanks,
>
> jwe
>

I've committed a changeset with the replacement routines. Also, the
first attempt to use them will issue a warning.
I haven't done any testing of the replacements beyond running make check.

regards

-- 
RNDr. Jaroslav Hajek
computing expert
Aeronautical Research and Test Institute (VZLU)
Prague, Czech Republic
url: www.highegg.matfyz.cz