csyr(3F)

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

     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.