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.

UPLO

          UPLO is 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

          N is INTEGER


           On entry, N specifies the order of the matrix A.


           N must be at least zero.


           Unchanged on exit.

ALPHA

          ALPHA is COMPLEX


           On entry, ALPHA specifies the scalar alpha.


           Unchanged on exit.

X

          X is 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

          INCX is INTEGER


           On entry, INCX specifies the increment for the elements of


           X. INCX must not be zero.


           Unchanged on exit.

A

          A is 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

          LDA is 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.

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NAG Ltd.

December 2016