redhat man page for zsyr

ZSYR(l) 								 )								   ZSYR(l)

NAME
       ZSYR - perform the symmetric rank 1 operation  A := alpha*x*( x' ) + A,

SYNOPSIS
       SUBROUTINE ZSYR( UPLO, N, ALPHA, X, INCX, A, LDA )

	   CHARACTER	UPLO

	   INTEGER	INCX, LDA, N

	   COMPLEX*16	ALPHA

	   COMPLEX*16	A( LDA, * ), X( * )

PURPOSE
       ZSYR 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*16
	      On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

       X      - COMPLEX*16 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*16 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 tri-
	      angular 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 							   ZSYR(l)