[petsc-users] Does KSPSetInitialGuessNonzero mean that x with initial values and will be updated?

[Brian Yang]

Sorry, yeah, I mean KSPSolve using iterative ways like LSQR, CG and etc.

Thanks.

On Tue, Nov 4, 2014 at 2:20 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
> > On Nov 4, 2014, at 2:13 PM, Brian Yang <brianyang1106 at gmail.com> wrote:
> >
> > Hi all,
> >
> > I am trying to solve Ax=0 with an initial values of x. I know
> KSPSetInitialGuessNonzero is
> > able to disable the zero guess, so it will keep updating the initial x
> right?
>
>    What do you mean by "it will keep updating the initial x right"?  What
> is "it" and what do you mean by "keep updating".
>
>    If you have not called KSPSetInitialGuessNonzero() then KSPSolve() will
> automatically zero x before starting the iteration. If you do call
> KSPSetInitialGuessNonzero() then KSPSolve will not automatically zero x
> before starting the iteration. That is all it does.
>
>   Barry
>
> >
> > Thanks.
> >
> > --
> > Brian Yang
> > U of Houston
> >
> >
> >
>
>


-- 
Brian Yang
U of Houston
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20141104/2c45c2bd/attachment.html>