CSYR
November 2006
Purpose
CSYR performs the symmetric rank 1 operation
A := alpha*x*x**H + A,
where alpha is a complex scalar, x is an n element vector and A is an
n by n symmetric matrix.
A := alpha*x*x**H + A,
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 referenced. 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 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 |
(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. |