ssymv
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(*)
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
#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 element 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.