Contents
ssymv - perform the matrix-vector operation y := alpha*A*x
+ beta*y
SUBROUTINE SSYMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
CHARACTER * 1 UPLO
INTEGER N, LDA, INCX, INCY
REAL ALPHA, BETA
REAL A(LDA,*), X(*), Y(*)
SUBROUTINE SSYMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
CHARACTER * 1 UPLO
INTEGER*8 N, LDA, INCX, INCY
REAL ALPHA, BETA
REAL A(LDA,*), X(*), Y(*)
F95 INTERFACE
SUBROUTINE SYMV(UPLO, [N], ALPHA, A, [LDA], X, [INCX], BETA, Y, [INCY])
CHARACTER(LEN=1) :: UPLO
INTEGER :: N, LDA, INCX, INCY
REAL :: ALPHA, BETA
REAL, DIMENSION(:) :: X, Y
REAL, DIMENSION(:,:) :: A
SUBROUTINE SYMV_64(UPLO, [N], ALPHA, A, [LDA], X, [INCX], BETA, Y,
[INCY])
CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, LDA, INCX, INCY
REAL :: ALPHA, BETA
REAL, DIMENSION(:) :: X, Y
REAL, DIMENSION(:,:) :: A
C INTERFACE
#include <sunperf.h>
void ssymv(char uplo, int n, float alpha, float *a, int lda,
float *x, int incx, float beta, float *y, int
incy);
void ssymv_64(char uplo, long n, float alpha, float *a, long
lda, float *x, long incx, float beta, float *y,
long incy);
ssymv performs the matrix-vector operation y := alpha*A*x +
beta*y, where alpha and beta are scalars, x and y are n ele-
ment vectors and A is an n by n symmetric matrix.
UPLO (input)
On entry, UPLO specifies whether the upper or
lower triangular part of the array A is to be
referenced as follows:
UPLO = 'U' or 'u' Only the upper triangular part
of A is to be referenced.
UPLO = 'L' or 'l' Only the lower triangular part
of A is to be referenced.
Unchanged on exit.
N (input)
On entry, N specifies the order of the matrix A.
N >= 0. Unchanged on exit.
ALPHA (input)
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
A (input)
Before entry with UPLO = 'U' or 'u', the leading
n by n upper triangular part of the array A must
contain the upper triangular part of the symmetric
matrix and the strictly lower triangular part of A
is not referenced. Before entry with UPLO = 'L'
or 'l', the leading n by n lower triangular part
of the array A must contain the lower triangular
part of the symmetric matrix and the strictly
upper triangular part of A is not referenced.
Unchanged on exit.
LDA (input)
On entry, LDA specifies the first dimension of A
as declared in the calling (sub) program. LDA >=
max( 1, n ). Unchanged on exit.
X (input)
( 1 + ( n - 1 )*abs( INCX ) ). Before entry, the
incremented array X must contain the n element
vector x. Unchanged on exit.
INCX (input)
On entry, INCX specifies the increment for the
elements of X. INCX <> 0. 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 + ( n - 1 )*abs( INCY ) ). Before entry, the
incremented array Y must contain the n element
vector y. On exit, Y is overwritten by the updated
vector y.
INCY (input)
On entry, INCY specifies the increment for the
elements of Y. INCY <> 0. Unchanged on exit.