Re: Linear Algebra in C++
On Feb 18, 10:24 pm, Rui Maciel <rui.mac...@gmail.com> wrote:
et al. wrote:
Hi! I am looking for some linear algebra libraries in C++... without
much success!
Basically, I found that BLAS and LAPACK can, somehow, be interacted
with in C++. However, the whole OO approach of C++ is lost (at least to
my sight).
Do you have any suggestions, apart from building my own wrapper? :)
OO stuff is usually kept out of numerical stuff mainly due to the fact
that it provides ways to abstract data and concepts that, as a side
effect, add undesired performance penalties to the routines.
I don't know if performance is the only reason (although it
certainly plays a role). A more fundamental reason is that for
the numeric processing, OO doesn't buy you anything. (This
doesn't mean that it's not useful for the surrounding layers,
which manage the calculations.)
[...]
On the other and, C++ does provide support for templates, and they are
indeed useful.
It depends on the type of numeric work you're doing. But for
anything using vectors or matrixes, you'll probably want some
form of expression analysis along the lines of that used in
blitz++. It can be done with derivation (with surprisingly no
real additional runtime overhead), but it's a lot easier using
templates. (And the inheritance used in the pre-template
versions isn't really what I would call OO.)
The more or less "standard" library for matrices and such is
blitz++ (or at least it was, but I haven't heard of anything
recent which would replace it).
--
James Kanze