CSYR(l) ) CSYR(l)NAME
CSYR - perform the symmetric rank 1 operation A := alpha*x*( x' ) + A,
SYNOPSIS
SUBROUTINE CSYR( UPLO, N, ALPHA, X, INCX, A, LDA )
CHARACTER UPLO
INTEGER INCX, LDA, N
COMPLEX ALPHA
COMPLEX A( LDA, * ), X( * )
PURPOSE
CSYR performs the symmetric rank 1 operation A := alpha*x*( x' ) + A,
where alpha is a complex scalar, x is an n element vector 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.
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.
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. On exit, the upper triangular part
of the array A is overwritten by the upper triangular part of
the updated matrix. 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. On exit,
the lower triangular part of the array A is overwritten by the
lower triangular part of the updated matrix.
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.
LAPACK version 3.0 15 June 2000 CSYR(l)
