CSYMV(l) ) CSYMV(l)NAME
CSYMV - perform the matrix-vector operation y := alpha*A*x + beta*y,
SYNOPSIS
SUBROUTINE CSYMV( UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY )
CHARACTER UPLO
INTEGER INCX, INCY, LDA, N
COMPLEX ALPHA, BETA
COMPLEX A( LDA, * ), X( * ), Y( * )
PURPOSE
CSYMV 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 - CHARACTER*1
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 - INTEGER
On entry, N specifies the order of the matrix A. N must be at
least zero. Unchanged on exit.
ALPHA - COMPLEX
On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
A - COMPLEX array, dimension ( LDA, N )
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 - INTEGER
On entry, LDA specifies the first dimension of A as declared in
the calling (sub) program. LDA must be at least max( 1, N ).
Unchanged on exit.
X - COMPLEX array, dimension at least
( 1 + ( N - 1 )*abs( INCX ) ). Before entry, the incremented
array X must contain the N- element vector x. Unchanged on
exit.
INCX - INTEGER
On entry, INCX specifies the increment for the elements of X.
INCX must not be zero. Unchanged on exit.
BETA - COMPLEX
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 - COMPLEX array, dimension at least
( 1 + ( N - 1 )*abs( INCY ) ). Before entry, the incremented
array Y must contain the n element vector y. On exit, Y is over‐
written by the updated vector y.
INCY - INTEGER
On entry, INCY specifies the increment for the elements of Y.
INCY must not be zero. Unchanged on exit.
LAPACK version 3.0 15 June 2000 CSYMV(l)
