MatMatTransposeMult#
Performs matrix-matrix multiplication C=A*B^T.
Synopsis#
#include "petscmat.h"
PetscErrorCode MatMatTransposeMult(Mat A, Mat B, MatReuse scall, PetscReal fill, Mat *C)
Neighbor-wise Collective
Input Parameters#
A - the left matrix
B - the right matrix
scall - either
MAT_INITIAL_MATRIXorMAT_REUSE_MATRIXfill - expected fill as ratio of nnz(C)/(nnz(A) + nnz(B)), use
PETSC_DEFAULTif not known
Output Parameter#
C - the product matrix
Notes#
C will be created if MAT_INITIAL_MATRIX and must be destroyed by the user with MatDestroy().
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 only implemented for pairs of MATSEQAIJ matrices, for the MATSEQDENSE class,
and for pairs of MATMPIDENSE matrices.
This routine is shorthand for using MatProductCreate() with the MatProductType of MATPRODUCT_ABt
Options Database Keys#
-matmattransmult_mpidense_mpidense_via {allgatherv,cyclic} - Choose between algorithms for
MATMPIDENSEmatrices: the first redundantly copies the transposed B matrix on each process and requires O(log P) communication complexity; the second never stores more than one portion of the B matrix at a time by requires O(P) communication complexity.
See Also#
Matrices, Mat, MatProductCreate(), MATPRODUCT_ABt, MatMatMult(), MatTransposeMatMult() MatPtAP(), MatProductCreate(), MatProductAlgorithm, MatProductType, MATPRODUCT_ABt
Level#
intermediate
Location#
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages