Contents
zgbmv - perform one of the matrix-vector operations y :=
alpha*A*x + beta*y, or y := alpha*A'*x + beta*y, or y :=
alpha*conjg( A' )*x + beta*y
SUBROUTINE ZGBMV(TRANSA, M, N, KL, KU, ALPHA, A, LDA, X, INCX,
BETA, Y, INCY)
CHARACTER * 1 TRANSA
DOUBLE COMPLEX ALPHA, BETA
DOUBLE COMPLEX A(LDA,*), X(*), Y(*)
INTEGER M, N, KL, KU, LDA, INCX, INCY
SUBROUTINE ZGBMV_64(TRANSA, M, N, KL, KU, ALPHA, A, LDA, X,
INCX, BETA, Y, INCY)
CHARACTER * 1 TRANSA
DOUBLE COMPLEX ALPHA, BETA
DOUBLE COMPLEX A(LDA,*), X(*), Y(*)
INTEGER*8 M, N, KL, KU, LDA, INCX, INCY
F95 INTERFACE
SUBROUTINE GBMV([TRANSA], [M], [N], KL, KU, ALPHA, A, [LDA], X,
[INCX], BETA, Y, [INCY])
CHARACTER(LEN=1) :: TRANSA
COMPLEX(8) :: ALPHA, BETA
COMPLEX(8), DIMENSION(:) :: X, Y
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER :: M, N, KL, KU, LDA, INCX, INCY
SUBROUTINE GBMV_64([TRANSA], [M], [N], KL, KU, ALPHA, A, [LDA],
X, [INCX], BETA, Y, [INCY])
CHARACTER(LEN=1) :: TRANSA
COMPLEX(8) :: ALPHA, BETA
COMPLEX(8), DIMENSION(:) :: X, Y
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER(8) :: M, N, KL, KU, LDA, INCX, INCY
C INTERFACE
#include <sunperf.h>
void zgbmv(char transa, int m, int n, int kl, int ku, doub-
lecomplex *alpha, doublecomplex *a, int lda, doub-
lecomplex *x, int incx, doublecomplex *beta,
doublecomplex *y, int incy);
void zgbmv_64(char transa, long m, long n, long kl, long ku,
doublecomplex *alpha, doublecomplex *a, long lda,
doublecomplex *x, long incx, doublecomplex *beta,
doublecomplex *y, long incy);
zgbmv performs one of the matrix-vector operations y :=
alpha*A*x + beta*y, or y := alpha*A'*x + beta*y, or y :=
alpha*conjg( A' )*x + beta*y where alpha and beta are
scalars, x and y are vectors and A is an m by n band matrix,
with kl sub-diagonals and ku super-diagonals.
TRANSA (input)
On entry, TRANSA specifies the operation to be
performed as follows:
TRANSA = 'N' or 'n' y := alpha*A*x + beta*y.
TRANSA = 'T' or 't' y := alpha*A'*x + beta*y.
TRANSA = 'C' or 'c' y := alpha*conjg( A' )*x +
beta*y.
Unchanged on exit.
TRANSA is defaulted to 'N' for F95 INTERFACE.
M (input)
On entry, M specifies the number of rows of the
matrix A. M must be at least zero. Unchanged on
exit.
N (input)
On entry, N specifies the number of columns of the
matrix A. N must be at least zero. Unchanged on
exit.
KL (input)
On entry, KL specifies the number of sub-diagonals
of the matrix A. KL must satisfy 0 .le. KL.
Unchanged on exit.
KU (input)
On entry, KU specifies the number of super-
diagonals of the matrix A. KU must satisfy 0 .le.
KU. Unchanged on exit.
ALPHA (input)
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
A (input)
Before entry, the leading ( kl + ku + 1 ) by n
part of the array A must contain the matrix of
coefficients, supplied column by column, with the
leading diagonal of the matrix in row ( ku + 1 )
of the array, the first super-diagonal starting at
position 2 in row ku, the first sub-diagonal
starting at position 1 in row ( ku + 2 ), and so
on. Elements in the array A that do not
correspond to elements in the band matrix (such as
the top left ku by ku triangle) are not refer-
enced. The following program segment will
transfer a band matrix from conventional full
matrix storage to band storage:
DO 20, J = 1, N
K = KU + 1 - J
DO 10, I = MAX( 1, J - KU ), MIN( M, J + KL
)
A( K + I, J ) = matrix( I, J )
10 CONTINUE
20 CONTINUE
Unchanged on exit.
LDA (input)
On entry, LDA specifies the first dimension of A
as declared in the calling (sub) program. LDA must
be at least ( kl + ku + 1 ). Unchanged on exit.
X (input)
( 1 + ( n - 1 )*abs( INCX ) ) when TRANSA = 'N' or
'n' and at least ( 1 + ( m - 1 )*abs( INCX ) )
otherwise. Before entry, the incremented array X
must contain the vector x. Unchanged on exit.
INCX (input)
On entry, INCX specifies the increment for the
elements of X. INCX must not be zero. Unchanged
on exit.
BETA (input)
On entry, BETA specifies the scalar beta. When
BETA is supplied as zero then Y need not be set on
input. Unchanged on exit.
Y (input/output)
( 1 + ( m - 1 )*abs( INCY ) ) when TRANSA = 'N' or
'n' and at least ( 1 + ( n - 1 )*abs( INCY ) )
otherwise. Before entry, the incremented array Y
must contain the vector y. On exit, Y is overwrit-
ten by the updated vector y.
INCY (input)
On entry, INCY specifies the increment for the
elements of Y. INCY must not be zero. Unchanged
on exit.