On Wed, Sep 28, 2011 at 4:15 PM, Hui Zhang <mike.hui.zhang@hotmail.com> wrote:

On Sep 28, 2011, at 6:08 PM, Matthew Knepley wrote:

On Wed, Sep 28, 2011 at 4:05 PM, Hui Zhang <mike.hui.zhang@hotmail.com> wrote:

On Sep 28, 2011, at 5:58 PM, Matthew Knepley wrote:

On Wed, Sep 28, 2011 at 3:54 PM, Hui Zhang <mike.hui.zhang@hotmail.com> wrote:

Hi all,

When using

PetscErrorCode  VecScatterCreate(Vec xin,IS ix,Vec yin,IS iy,VecScatter *newctx)

I want to add those values of xin to the original values of yin.

Is there a way to do this without copy of yin?

I am not sure what you mean here. Do you want xin == yin?

No, I mean part of xin is going to be added to part of yin.

Alright. We do not make a copy of yin.

My fault, the question is not clear. I mean 'add' as 'sum'. I want the resultant 'yin' to have values 

y(iy) = y(iy) + x(ix).

Use ADD_VALUES in VecScatterBegin/End()

   Matt

 

   Matt

 

  Matt

 

Thanks!

Hui

--
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

--
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

--
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