ssymv(3P) Sun Performance Library ssymv(3P)NAMEssymv - perform the matrix-vector operation y := alpha*A*x + beta*y
SYNOPSIS
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);
PURPOSEssymv performs the matrix-vector operation y := alpha*A*x + beta*y,
where alpha and beta are scalars, x and y are n element vectors and A
is an n by n symmetric matrix.
ARGUMENTS
UPLO (input)
On entry, UPLO specifies whether the upper or lower triangu‐
lar 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 sup‐
plied 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.
6 Mar 2009 ssymv(3P)
