MXYTF
Multiplies a matrix A by the transpose of a matrix B, ABT.
Required Arguments
A — Real NRA by NCA rectangular matrix. (Input)
B — Real NRB by NCB rectangular matrix. (Input)
C — Real NRC by NCC rectangular matrix containing the transpose product ABT. (Output)
Optional Arguments
NRA — Number of rows in A. (Input)
Default: NRA = SIZE (A,1).
NCA — Number of columns in A. (Input)
Default: NCA = SIZE (A,2).
LDA — Leading dimension of A exactly as specified in the dimension statement of the calling program. (Input)
Default: LDA = SIZE (A,1).
NRB — Number of rows in B. (Input)
Default: NRB = SIZE (B,1).
NCB — Number of columns in B. (Input)
NCB must be the same as NCA.
Default: NCB = SIZE (B,2).
LDB — Leading dimension of B exactly as specified in the dimension statement of the calling program. (Input)
Default: LDB = SIZE (B,1).
NRC — Number of rows of C. (Input)
NRC must be equal to NRA.
Default: NRC = SIZE (C,1).
NCC — Number of columns of C. (Input)
NCC must be equal to NRB.
Default: NCC = SIZE (C,2).
LDC — Leading dimension of C exactly as specified in the dimension statement of the calling program. (Input)
Default: LDC = SIZE (C,1).
FORTRAN 90 Interface
Generic: CALL MXYTF (A, B, C [, …])
Specific: The specific interface names are S_MXYTF and D_MXYTF.
FORTRAN 77 Interface
Single: CALL MXYTF (NRA, NCA, A, LDA, NRB, NCB, B, LDB, NRC, NCC, C, LDC)
Double: The double precision name is DMXYTF.
Description
The routine MXYTF computes the real general matrix C = ABT given the real rectangular matrices A and B.
Example
Multiply a 3 × 4 real matrix by the transpose of a 3 × 4 real matrix. The output matrix will be a 3 × 3 real matrix.
USE MXYTF_INT
USE WRRRN_INT
IMPLICIT NONE
! Declare variables
INTEGER NCA, NCB, NCC, NRA, NRB, NRC
PARAMETER (NCA=4, NCB=4, NCC=3, NRA=3, NRB=3, NRC=3)
!
REAL A(NRA,NCA), B(NRB,NCB), C(NRC,NCC)
! Set values for A
! A = ( 1.0 0.0 2.0 0.0 )
! ( 3.0 4.0 -1.0 0.0 )
! ( 2.0 1.0 2.0 1.0 )
!
! Set values for B
! B = ( -1.0 2.0 0.0 2.0 )
! ( 3.0 0.0 -1.0 -1.0 )
! ( 0.0 5.0 2.0 5.0 )
!
DATA A/1.0, 3.0, 2.0, 0.0, 4.0, 1.0, 2.0, -1.0, 2.0, 0.0, 0.0, &
1.0/
DATA B/-1.0, 3.0, 0.0, 2.0, 0.0, 5.0, 0.0, -1.0, 2.0, 2.0, -1.0, &
5.0/
! Compute C = A*trans(B)
CALL MXYTF (A, B, C)
! Print results
CALL WRRRN ('C = A*trans(B)', C)
END
Output
C = A*trans(B)
1 2 3
1 -1.00 1.00 4.00
2 5.00 10.00 18.00
3 2.00 3.00 14.00
