Converts a complex general matrix to a matrix in complex band storage mode.

Required Arguments

A — Complex N by N array containing the matrix.   (Input)

NLC — Number of lower codiagonals in B.   (Input)

NUC — Number of upper codiagonals in B.   (Input)

B — Complex (NUC + 1 + NLC) by N array containing the band matrix in band storage mode.   (Output)

Optional Arguments

N — Order of the matrices A and B.   (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).

FORTRAN 90 Interface

Generic:          CALL CCGCB (A, NLC, NUC, B [,…])

Specific:         The specific interface names are S_CCGCB and D_CCGCB.

FORTRAN 77 Interface

Single:             CALL CCGCB (N, A, LDA, NLC, NUC, B, LDB)

Double:          The double precision name is DCCGCB.

Description

The routine CCGCB converts the complex general matrix A of order N with mu = NUC upper codiagonals and ml = NLC lower codiagonals into the complex band matrix B of order N in band storage mode. The first mu rows of B then contain the upper codiagonals of A, the next row contains the main diagonal of A, and the last ml rows of B contain the lower codiagonals of A.

Example

A complex general matrix of order 4 with one upper codiagonal and three lower codiagonals is copied to a complex band matrix of order 4 in band storage mode.

 

      USE CCGCB_INT

      USE WRCRN_INT

 

      IMPLICIT   NONE

!                                 Declare variables

      INTEGER    LDA, LDB, N, NLC, NUC

      PARAMETER  (LDA=4, LDB=5, N=4, NLC=3, NUC=1)

!

      COMPLEX    A(LDA,N), B(LDB,N)

!                     Set values for  A

!                     A = (  1.0+0.0i   2.0+1.0i  0.0+0.0i  0.0+0.0i )

!                         ( -2.0+1.0i   1.0+0.0i  3.0+2.0i  0.0+0.0i )

!                         (  0.0+0.0i  -3.0+2.0i  1.0+0.0i  4.0+3.0i )

!                         ( -7.0+1.0i   0.0+0.0i -4.0+3.0i  1.0+0.0i )

!

      DATA A/(1.0,0.0), (-2.0,1.0), (0.0,0.0), (-7.0,1.0), (2.0,1.0), &

          (1.0,0.0), (-3.0,2.0), (0.0,0.0), (0.0,0.0), (3.0,2.0), &

          (1.0,0.0), (-4.0,3.0), (0.0,0.0), (0.0,0.0), (4.0,3.0), &

          (1.0,0.0)/

!                                 Convert A to band matrix B

      CALL CCGCB (A, NLC, NUC, B)

!                                 Print results

      CALL WRCRN ('B', B)

      END

Output

 

                                 B
                 1                2                3                4
1  ( 0.000, 0.000)  ( 2.000, 1.000)  ( 3.000, 2.000)  ( 4.000, 3.000)
2  ( 1.000, 0.000)  ( 1.000, 0.000)  ( 1.000, 0.000)  ( 1.000, 0.000)
3  (-2.000, 1.000)  (-3.000, 2.000)  (-4.000, 3.000)  ( 0.000, 0.000)
4  ( 0.000, 0.000)  ( 0.000, 0.000)  ( 0.000, 0.000)  ( 0.000, 0.000)
5  (-7.000, 1.000)  ( 0.000, 0.000)  ( 0.000, 0.000)  ( 0.000, 0.000)

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