MXTYF
Multiplies the transpose of matrix A by matrix B, ATB.
Required Arguments
A — Real NRA by NCA matrix. (Input)
B — Real NRB by NCB matrix. (Input)
C — Real NCA by NCB matrix containing the transpose product ATB. (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)
NRB must be the same as NRA.
Default: NRB = SIZE (B,1).
NCB — Number of columns in B. (Input)
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 NCA.
Default: NRC = SIZE (C,1).
NCC — Number of columns of C. (Input)
NCC must be equal to NCB.
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 MXTYF (A, B, C [, …])
Specific: The specific interface names are S_MXTYF and D_MXTYF.
FORTRAN 77 Interface
Single: CALL MXTYF (NRA, NCA, A, LDA, NRB, NCB, B, LDB, NRC, NCC, C, LDC)
Double: The double precision name is DMXTYF.
Description
The routine MXTYF computes the real general matrix C = ATB given the real rectangular matrices A and B.
Example
Multiply the transpose of a 3 × 4 real matrix by a 3 × 3 real matrix. The output matrix will be a 4 × 3 real matrix.
USE MXTYF_INT
USE WRRRN_INT
IMPLICIT NONE
! Declare variables
INTEGER NCA, NCB, NCC, NRA, NRB, NRC
PARAMETER (NCA=4, NCB=3, NCC=3, NRA=3, NRB=3, NRC=4)
!
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 )
! ( 3.0 0.0 -1.0 )
! ( 0.0 5.0 2.0 )
!
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/
! Compute C = trans(A)*B
CALL MXTYF (A, B, C)
! Print results
CALL WRRRN ('C = trans(A)*B', C)
END
C = trans(A)*B
1 2 3
1 8.00 12.00 1.00
2 12.00 5.00 -2.00
3 -5.00 14.00 5.00
4 0.00 5.00 2.00
