Manav,

  For parallel sparse matrices using the standard PETSc formats the matrix is 
stored in two parts on each process (see the details in MatCreateAIJ()) thus 
there is no inexpensive way to access directly the IJ locations as a single 
local matrix. What are you hoping to use the information for? Perhaps we have 
other suggestions on how to achieve the goal.

   Barry


> On May 29, 2019, at 2:27 PM, Manav Bhatia via petsc-users 
> <petsc-users@mcs.anl.gov> wrote:
> 
> Hi, 
> 
>    Once a MPI-AIJ matrix has been assembled, is there a method to get the 
> nonzero I-J locations? I see one for sequential matrices here: 
> https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatGetRowIJ.html
>  , but not for parallel matrices. 
> 
> Regards,
> Manav
> 
> 

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