petsc-3.10.2 2018-10-09
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MatMatMatMult

Performs Matrix-Matrix-Matrix Multiplication D=A*B*C.

Synopsis

#include "petscmat.h" 
PetscErrorCode MatMatMatMult(Mat A,Mat B,Mat C,MatReuse scall,PetscReal fill,Mat *D)
Neighbor-wise Collective on Mat

Input Parameters

A - the left matrix
B - the middle matrix
C - the right matrix
scall - either MAT_INITIAL_MATRIX or MAT_REUSE_MATRIX
fill - expected fill as ratio of nnz(D)/(nnz(A) + nnz(B)+nnz(C)), use PETSC_DEFAULT if you do not have a good estimate if the result is a dense matrix this is irrelevent

Output Parameters

D -the product matrix

Notes

Unless scall is MAT_REUSE_MATRIX D will be created.

MAT_REUSE_MATRIX can only be used if the matrices A, B and C 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.

If you have many matrices with the same non-zero structure to multiply, you should use MAT_REUSE_MATRIX in all calls but the first or

See Also

MatMatMult, MatPtAP()

Level

intermediate

Location

src/mat/interface/matrix.c

Implementations

MatMatMatMult_Transpose_AIJ_AIJ in src/mat/impls/aij/mpi/mpimatmatmatmult.c
MatMatMatMult_MPIAIJ_MPIAIJ_MPIAIJ in src/mat/impls/aij/mpi/mpimatmatmatmult.c
MatMatMatMult_SeqAIJ_SeqAIJ_SeqAIJ in src/mat/impls/aij/seq/matmatmatmult.c

Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages