Re: indexing expression performance

[Jaroslav Hajek]

On Fri, Jan 16, 2009 at 3:07 PM, Jordi Gutiérrez Hermoso
<address@hidden> wrote:
> 2009/1/16 Thomas Weber <address@hidden>:
>> Am Freitag, den 16.01.2009, 10:01 +0100 schrieb Jaroslav Hajek:
>>> Btw., I see Debian has a pretty complete octave3.0 package.
>>> How hard would be packaging the qrupdate library for Debian?
>>> (https://sourceforge.net/projects/qrupdate).
>>
>> Good question. I don't have much experience with packaging libraries.
>> The biggest problem are incompatible changes to the library's interface,
>> which means a proper SONAME.
>>
>> It's somewhat complicated by the fact that the library uses Fortran. For
>> C/C++, you have knowledgable people at every corner. How much do you
>> expect the library to change in the future?
>
> Well, we have some docs... I'm sure you've found them already:
>
>      http://packages.debian.org/sid/libpkg-guide
>
> But beware
>
>      http://bugs.debian.org/libpkg-guide
>
> I didn't quite follow the discussion, so please tell me again why it's
> desirable to package this library?
>

Octave uses it to implement the qrupdate, qrinsert, qrdelete, qrshift,
cholupdate, cholinsert, choldelete and cholshift functions. Up to now
a snapshot of version 0 of the lib was included directly in Octave
sources. During December I finally got to rewriting the library to get
a more robust interface and incorporate various improvements, and I
released it (it was GPLed from the beg) on SourceForge.
It is of course possible to carry on the inclusion in libcruft, but my
impression is that it is sort of the opposite direction we normally
go, so now I aim to remove it and simply check for qrupdate during
configure, disabling the relevant functionality if it is not found (we
do the same thing with other libs).
For those who build Octave from sources there is hardly a difference
(except that keeping a lib separate allows separate building), but it
has been pointed out that in a distro, a library needs to be packaged
and that can be problematic.
So, the question is, how much effort does it take to package a
(Fortran) library?
Will someone be willing to do it? I could probably help, if I'm told how.
I really have little knowledge here.
To make it more clear, if such a change is likely to results in the
state when in all distros you will get Octave without qrupdate, it may
be better to keep it in libcruft.

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