Eigen, a shared linear algebra library for KDE apps

[Cyrille Berger]

Well we talk a lot about it on irc (#koffice, not really the most obvious 
place to discuss this ;) , but apparently the people interested by that 
library happen to be there at the same time.)

So first, the discussion was to choose the same dependency for all kde 
application interested in a basic linear algebraic system, so there was 
discussion about vxl/vnl, boost/ublas (+lapack), gsl, whatever. But there was 
some concern about the "size" of this dependency, while nowdays hard drive 
are huge and a dependency of 5 Mo to 10 Mo is acceptable even if you only use 
a subset of the functionality of this library, some of the concerned 
application (kalzium and marble, mostly kphysics too probably) are also 
shipped on live CD where disk space is still a problem.

So the first idea was to use (for instance) boost, which is template library, 
and therefor only bring a build time dependency. But then some developers 
were needing advanced functions (least square for instance) which required 
lapack, so the idea was to only copy/paste the concerned functions into the 
applications. That's how the idea to have our own library, and by reusing 
code from existing project, and if this code is C based, to transform it to 
be C++.

On Thursday 27 July 2006 20:00, Kleag wrote:
> Hello,
>
> Don't know if it has all what you want, but ublas, part of the boost
> libraries, (http://www.boost.org/libs/numeric/ublas/doc/overview.htm) has
> vectors, matrices, solving of systems of linear equations...
>
> Well, I did not use this library myself, just read the doc introduction,
> but as a user of other Boost libraries, I'm usualy very happy with them.
>
> Regards,
>
> Kleag
>
> Le jeudi 27 juillet 2006 17:38, Casper Boemann a écrit :
> > Hi
> >
> > The developers of Kalzium, Kreative3D, KChart and Marble have a common
> > need for a simple linear algebra library. We had a lengthy IRC discussion
> > and searched existing libraries, but they are usually big, non C++ etc,
> > and having big dependencies makes us afraid of being excluded from some
> > distros.
> >
> > So we have decided to work together with the aim of creating a simple
> > linear algebra library called Eigen (a little wordplay), which we would
> > like to place within KDE.
> >
> > The idea of the library is to create the interface we want and then copy
> > actual code from the tons of math libs out there. Basically all we want
> > is a Vector and a Matrix class and the usaual +, -, * operations plus dot
> > product, crossed product, and a way to construct orthogonal vectors and
> > bases.
> >
> > We want Quaternions and functions to solve systems of linear equations,
> > but that is it.
> >
> > Main question is where in the KDE directory structure can we put this?

-- 
--- Cyrille Berger ---