On Friday, 14 August 2015 at 14:57:19 UTC, Andrei Alexandrescu
wrote:
No doubt other popular linear algebra libraries have similar
documentation. I was thinking we could start with adding these
layouts to std, along with a few simple primitives
(construction, element/slice access, stride etc). Then, people
may just use those as they are or link with the linalg
libraries for specific computations.
Thoughts?
Andrei
For comparison, some other sparse linear algebra libraries worth
looking at are:
* Eigen (http://eigen.tuxfamily.org/)
* PETSc (http://www.mcs.anl.gov/petsc/)
* the Epetra sub-package of Trilinos (https://trilinos.org/)
* OSKI, which aims to do for sparse matrices what ATLAS does for
dense (http://bebop.cs.berkeley.edu/oski/)
MKL is missing some important sparse matrix formats -- the
ellpack and jagged diagonal formats, which are very well suited
for SIMD processors, and the MSR/MSC format, which makes
multigrid smoothing faster.
I don't know enough to weigh in on whether sparse matrix algebra
is best left to the individual libraries or put in the language's
standard library. It's common practice whenever one needs sparse
matrices to write wrapper classes that can use either PETSc or
Trilinos, depending on what the users have installed on their
systems. For example, this is the approach taken in the finite
element library deal.II (http://dealii.org/). Moreover, the big
sparse matrix libraries can all use each other; PETSc can link to
the solvers in Trilinos, both PETSc and Trilinos can link to
OSKI, etc. If there were some support in the standard library for
this functionality, it could obviate the need for some of the
glue code in C/C++.
