ACBCB

Adds two complex band matrices, both in band storage mode.

Required Arguments

A — N by N complex band matrix with NLCA lower codiagonals and NUCA upper codiagonals stored in band mode with dimension (NLCA + NUCA + 1) by N. (Input)

NLCA — Number of lower codiagonals of A. (Input)

NUCA — Number of upper codiagonals of A. (Input)

B — N by N complex band matrix with NLCB lower codiagonals and NUCB upper codiagonals stored in band mode with dimension (NLCB + NUCB + 1) by N. (Input)

NLCB — Number of lower codiagonals of B. (Input)

NUCB — Number of upper codiagonals of B. (Input)

C — N by N complex band matrix with NLCC lower codiagonals and NUCC upper codiagonals containing the sum A + B in band mode with dimension (NLCC + NUCC + 1) by N. (Output)

NLCC — Number of lower codiagonals of C. (Input)
NLCC must be at least as large as max(NLCA, NLCB).

NUCC — Number of upper codiagonals of C. (Input)
NUCC must be at least as large as max(NUCA, NUCB).

Optional Arguments

N — Order of the matrices A, B and C. (Input)
Default: N = 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).

LDB — Leading dimension of B exactly as specified in the dimension statement of the calling program. (Input)
Default: LDB = SIZE (B,1).

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 ACBCB (A, NLCA, NUCA, B, NLCB, NUCB, C, NLCC, NUCC [, …])

Specific: The specific interface names are S_ACBCB and D_ACBCB.

FORTRAN 77 Interface

Single: CALL ACBCB (N, A, LDA, NLCA, NUCA, B, LDB, NLCB, NUCB, C, LDC, NLCC, NUCC)

Double: The double precision name is DACBCB.

Description

The routine ACBCB adds two complex matrices stored in band mode, returning a complex matrix stored in band mode.

Example

Add two complex matrices of order 4 stored in band mode. Matrix A has two upper codiagonals and no lower codiagonals. Matrix B has no upper codiagonals and two lower codiagonals. The output matrix C has two upper codiagonals and two lower codiagonals.

 

USE ACBCB_INT

USE WRCRN_INT

 

IMPLICIT NONE

! Declare variables

INTEGER LDA, LDB, LDC, N, NLCA, NLCB, NLCC, NUCA, NUCB, NUCC

PARAMETER (LDA=3, LDB=3, LDC=5, N=3, NLCA=0, NLCB=2, NLCC=2, &

NUCA=2, NUCB=0, NUCC=2)

!

COMPLEX A(LDA,N), B(LDB,N), C(LDC,N)

! Set values for A (in band mode)

! A = ( 0.0 + 0.0i 0.0 + 0.0i 3.0 - 2.0i )

! ( 0.0 + 0.0i -1.0+ 3.0i 6.0 + 0.0i )

! ( 1.0 + 4.0i 5.0 - 2.0i 3.0 + 1.0i )

!

! Set values for B (in band mode)

! B = ( 3.0 + 1.0i 4.0 + 1.0i 7.0 - 1.0i )

! ( -1.0- 4.0i 9.0 + 3.0i 0.0 + 0.0i )

! ( 2.0 - 1.0i 0.0 + 0.0i 0.0 + 0.0i )

!

DATA A/(0.0,0.0), (0.0,0.0), (1.0,4.0), (0.0,0.0), (-1.0,3.0), &

(5.0,-2.0), (3.0,-2.0), (6.0,0.0), (3.0,1.0)/

DATA B/(3.0,1.0), (-1.0,-4.0), (2.0,-1.0), (4.0,1.0), (9.0,3.0), &

(0.0,0.0), (7.0,-1.0), (0.0,0.0), (0.0,0.0)/

! Compute C = A+B

CALL ACBCB (A, NLCA, NUCA, B, NLCB, NUCB, C, NLCC, NUCC)

! Print results

CALL WRCRN ('C = A+B', C)

END

Output

 

C = A+B

1 2 3

1 ( 0.00, 0.00) ( 0.00, 0.00) ( 3.00, -2.00)

2 ( 0.00, 0.00) ( -1.00, 3.00) ( 6.00, 0.00)

3 ( 4.00, 5.00) ( 9.00, -1.00) ( 10.00, 0.00)

4 ( -1.00, -4.00) ( 9.00, 3.00) ( 0.00, 0.00)

5 ( 2.00, -1.00) ( 0.00, 0.00) ( 0.00, 0.00)