[petsc-dev] How do you get RIchardson?

[Jed Brown]

On Sat, Sep 17, 2011 at 01:24, Vijay S. Mahadevan <vijay.m at gmail.com> wrote:

> Also calling newton even without the matrix free jacobian with just Picard
> linearization with an algebraic preconditioner is sometimes more efficient.


Yes, these linear systems are usually easier to solve. For example, they may
have isotropic coefficients while Newton linearization effectively produces
anisotropic coefficients.

On the other hand, the nonlinear convergence is only linear and often
requires many more iterations than Newton, especially in the terminal phase.
This tradeoff is of course highly problem dependent.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20110917/9c88342b/attachment.html>