[petsc-users] Solving dense rectangular linear systems

[Rakesh Halder]

Hi all,

I'm wondering what the recommended method is to solve linear systems Ax=b,
where A is an N by n matrix (N >> n) and dense. I've used the CGLS and LSQR
algorithms, but have issues applying any kind of preconditioner. Looking at
the PETSc documentation, it doesn't look like there are any direct solvers
for rectangular systems, but only iterative ones which aren't very useful
for dense systems.

I'm also wondering if it's best to use a dense or sparse (AIJ) matrix
format in general when working with dense matrices. I've just been using
sparse matrices, due to being able to preallocate memory.

Thanks,

Rakesh Halder
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20201108/65d73b14/attachment.html>