[petsc-users] Implementing a homotopy solver

[Matthew Knepley]

On Tue, Jul 17, 2018 at 1:32 PM zakaryah <zakaryah at gmail.com> wrote:

> Thanks Matt.
>
>>
>>
>>> 2) Is there a way to reuse the KSP for (1) to efficiently solve (2),
>>> given the method which answers question 1) ?
>>>
>>
>> Not really, unless you use some type of factorization for the
>> preconditioner.
>>
>
> Can you elaborate?
> ​I know that KSP can efficiently solve linear systems with the same matrix
> but different right-hand sides, just by calling KSPSolve successively.
> Will this be impossible within the nonlinear solver after calculating the
> nullspace?​
>
>>
This is what I was referring to. KSP reuse only works if you have some
factorization preconditioner. In that case, KSP
will keep it around if you call KSPSolve() again with a different rhs. You
can do that same thing in your case.

  Thanks,

     Matt
-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener

https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20180718/eb624d41/attachment.html>