#include "petscmat.h" PetscErrorCode MatTransposeMatMult(Mat A,Mat B,MatReuse scall,PetscReal fill,Mat *C)Neighbor-wise Collective on Mat
|A||- the left matrix|
|B||- the right matrix|
|scall||- either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX|
|fill||- expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use PETSC_DEFAULT if not known|
|C||- the product matrix|
MAT_REUSE_MATRIX can only be used if the matrices A and B have the same nonzero pattern as in the previous call.
To determine the correct fill value, run with -info and search for the string "Fill ratio" to see the value actually needed.
This routine is currently implemented for pairs of AIJ matrices and pairs of SeqDense matrices and classes which inherit from SeqAIJ. C will be of same type as the input matrices.