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

Output

 

      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

Visual Numerics, Inc. Visual Numerics - Developers of IMSL and PV-WAVE http://www.vni.com/ PHONE: 713.784.3131 FAX:713.781.9260