[petsc-users] tridiagonal matrix in kspsolve
Jed Brown
jed at jedbrown.org
Tue Jun 10 18:02:41 CDT 2014
Shriram Srinivasan <shriram at ualberta.ca> writes:
> Apologies if my question is answered elsewhere already. I could not
> find this discussed in the manual or mailing list.
>
> I have been using matsolvermumps through ksp to solve my linear system.
> I wanted to simply get it working so I was not concerned about the
> structure of the matrix.
>
>
> 1) My matrix is tridiagonal, but the elements of the diagonals are not
> all equal. Will a dedicated tridiagonal solver be faster than
> matsolvermumps in this case ?
>
> 2) My matrix is tridiagonal but not in the conventional sense, the minor
> diagonals are farther apart. But it is possible to renumber the nodes
> and make it a conventional tridiagonal system. In this case, again, am I
> losing efficiency using matsolvermumps ?
Yes on all counts, but use a profiler to see where the time is spent. A
good implementation will specialize the tridiagonal structure and
aggregate all the problems. It can be done efficiently, but I'm not
aware of general-purpose libraries.
However, I reiterate my earlier statements that ADI is an antiquated
method that has fallen out of favor since it is a poor parallel
algorithm and has large splitting errors.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 818 bytes
Desc: not available
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20140611/78be6167/attachment-0001.pgp>
More information about the petsc-users
mailing list