CSYR(1) LAPACK auxiliary routine (version 3.2) CSYR(1)NAME
CSYR - performs 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 where alpha is a complex
scalar, x is an n element vector and A is an n by n symmetric matrix.
ARGUMENTS
UPLO (input) 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 refer‐
enced. UPLO = 'L' or 'l' Only the lower triangular part of
A is to be referenced. Unchanged on exit.
N (input) INTEGER
On entry, N specifies the order of the matrix A. N must be at
least zero. Unchanged on exit.
ALPHA (input) COMPLEX
On entry, ALPHA specifies the scalar alpha. Unchanged on
exit.
X (input) 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 (input) INTEGER
On entry, INCX specifies the increment for the elements of X.
INCX must not be zero. Unchanged on exit.
A (input/output) 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 sym‐
metric 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 (input) 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 auxiliary routine (versioNovember 2008 CSYR(1)