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

[Barry Smith]

> 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
> 
> 
>