Re: ROOTCINT and linear algebra classes

Nick van Eijndhoven (Nick@fys.ruu.nl)
Wed, 10 Sep 1997 10:01:53 +0200 (MET DST)


Hi Valery,
Below follow my points of view on the matter.

Cheers,
Nick.

*----------------------------------------------------------------------*
Dr. Nick van Eijndhoven Department of Subatomic Physics
email : nick@fys.ruu.nl Utrecht University / NIKHEF
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WWW : http://www.fys.ruu.nl/~nick Office : Ornstein lab. 172
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tel. +41-22-7679751 (direct) CERN PPE Division / ALICE exp.
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*** Valery Fine wrote :
>
> On 8 Sep 97 at 21:15, Pasha Murat wrote:
>
> >
> >
> > I've been trying to figure out how to use linear algebra classes
> > with ROOT. There are 2 basically different types of linear algebra
> > packages on the market:
>
>
> I think there is means to address such sort of the question to
> CLHEP group of LHC++ project. Would they mind to create/compile a
> version of CLHEP share/dynamic libraries for all ROOT supported
> platform (or some of them at least). I don't think we are so rich
> with manpower to allow ourselves to make some job twice (and in
> different way).

==> I think we should be very clear here : Either LHC++ is provided
for ALL ROOT supported platforms or one should just forget it !
Just some of the platforms is not good enough, since this would mean
that the ROOT functionality will be different on different machines
and I think this is unacceptable !
The other concern I have is maintanance : The nice thing now is
that the ROOT package is absolutely standalone (I regard here CINT
as an integral part of ROOT). When ROOT needs certain LHC++ libs
we might easily run into compatibility problems and from experience
I know that (let me say it like this) 'CN is not extremely fast nor
efficient' in making updates when there is not a general need for it.
Here I would like to refer to my problem with the 50000 column limitation
for column wise ntuples in HBOOK (and PAW) which forced me to restructure
completely the output format of the ALICE detector simulation.
According to the real specialists this could have been fixed easily,
but the change was never introduced.
I am VERY satisfied with the speed and efficiency with which problems
are fixed and some requests are introduced in ROOT and CINT and it
would be a big disadvantage if this turnaround would be slowed down
because one would have to stay compatible with an external program
pool (like e.g. LHC++).
Understand me well, I don't say one should not use LHC++ but I would
like to see this as the responsability of the user and not as part
of the ROOT project.