how to get the MPIAIJ matrix information?

[Randall Mackie]

Yujie,

This is explained in the manual on page 59, under Preallocation of Memory
for Parallel AIJ Sparse Matrices.

Randy


Yujie wrote:
> Hi,
> 
> In MatCreateMPIAIJ() function, it needs d_nz, d_nnz[], o_nz, o_nnz[]. If 
> one has a MATAIJ matrix, how to obtian this information? thanks a lot.
> 
> PetscErrorCode PETSCMAT_DLLEXPORT MatCreateMPIAIJ(MPI_Comm comm,PetscInt 
> m,PetscInt n,PetscInt M,PetscInt N,PetscInt d_nz,const PetscInt 
> d_nnz[],PetscInt o_nz,const PetscInt o_nnz[],Mat *A)
> 
> Regards,
> 
> Yujie
>