[petsc-dev] Differences between injection and interpolation creation

[Barry Smith]

  I suggest you change the DM to return a matrix in this case and submit a pull request https://bitbucket.org/petsc/petsc/wiki/pull-request-instructions-git then we can get your suggested change into PETSc.

   Thanks

   Barry

> On Jan 13, 2015, at 9:45 AM, Lawrence Mitchell <lawrence.mitchell at imperial.ac.uk> wrote:
> 
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> Hi all,
> 
> is there a strong reason why DMCreateInjection builds a VecScatter
> rather than a Mat (unlike DMCreateInterpolation)?
> This seems to rule out creating an injection routine that does coarse
> cell averaging (for, e.g. FV problems).  When used in SNESFAS, the
> scatter from DMCreateInjection immediately gets wrapped up in a Mat
> anyway.
> 
> Cheers,
> 
> Lawrence
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