[petsc-users] KSPSetComputeRHS and KSPSetComputeOperators

[Matthew Knepley]

On Thu, Nov 21, 2013 at 5:44 PM, iwaddington . <iwaddington at gmail.com>wrote:

> HI everybody, I have a doubt concerning how the function KSPSetComputeRHS
> works, because according to its prototype one of its arguments is a pointer
> to a function that takes a vector object as argument, not a pointer towards
> a vector object, so how is it able to set the rhs if the passage of the
> vector is done by value and not by reference ?
>

The values of the Vec can be set, rather than changing the object pointer
itself.


> Another thing is the functioning of KSPSetComputeOperators. I want to set
> the linear system matrix and I want the preconditioning matrix to be equal,
> so can I just set the linar system matrix in the function that is argument
> of KSPSetComputeOperators, or do I need to make a matcopy in it ?
>

No, just give the same argument twice.

   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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20131121/2dbcc705/attachment.html>