We don’t currently have such a routine. You could copy MatSetValuesStencil() 
and MatSetValuesLocal() and produce MatGetValuesStencil() and 
MatGetValuesLocal() with very minor changes and get what you want.  You could 
consider contributing these back to PETSc with a pull request  see 
https://bitbucket.org/petsc/petsc/wiki/Home#markdown-header-contributing-a-larger-piece-of-functionality


   Barry

On Jul 13, 2014, at 12:49 PM, Xiangdong <[email protected]> wrote:

> Hello everyone,
> 
> I am just wondering whether there is a function doing the opposite of 
> MatSetValuesStencil. I tried to find a MatGetValues equivalent for using 
> structured grid indexing, but it seems that MatGetValuesStencil does not 
> exist.
> 
> I have a sparse matrix A built on DMDA. If I want to use A's entries to build 
> another DMDA matrices B, what is the best way to retrieve A's entries? Is it 
> possible to use grid indexing?
> 
> Thank you.
> 
> Best,
> Xiangdong

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