a question about tolerance
Jed Brown
jed at 59A2.org
Tue Sep 15 17:27:00 CDT 2009
Ryan Yan wrote:
> How can I explain the relative tolerance is function correctly? as you can
> see from the term ||Ae||/||Ax||, neither of my testruns seems to stop at the
> right place(should be 10^(-2), 10^(-3) respectively).
The ||Ae||/||Ax|| column is not the preconditioned norm. You are using
left-preconditioned GMRES (the default) which uses the preconditioned
norm. Use
-ksp_right_pc -ksp_norm_type unpreconditioned
for the behavior you seem to expect.
Jed
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 261 bytes
Desc: OpenPGP digital signature
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090915/816a6946/attachment.pgp>
More information about the petsc-users
mailing list