redhat man page for cspr

CSPR(l) 								 )								   CSPR(l)

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

SYNOPSIS
       SUBROUTINE CSPR( UPLO, N, ALPHA, X, INCX, AP )

	   CHARACTER	UPLO

	   INTEGER	INCX, N

	   COMPLEX	ALPHA

	   COMPLEX	AP( * ), X( * )

PURPOSE
       CSPR  performs the symmetric rank 1 operation A := alpha*x*conjg( x' ) + A, where alpha is a complex scalar, x is an n element vector and A
       is an n by n symmetric matrix, supplied in packed form.

ARGUMENTS
       UPLO   - CHARACTER*1
	      On entry, UPLO specifies whether the upper or lower triangular part of the matrix A is supplied in the packed array AP as follows:

	      UPLO = 'U' or 'u'   The upper triangular part of A is supplied in AP.

	      UPLO = 'L' or 'l'   The lower triangular part of A is supplied in AP.

	      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.

       AP     - COMPLEX array, dimension at least
	      ( ( N*( N + 1 ) )/2 ).  Before entry, with  UPLO = 'U' or 'u', the array AP must contain the upper triangular part of the  symmetric
	      matrix  packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 ) and a( 2, 2
	      ) respectively, and so on. On exit, the array AP is overwritten by the upper triangular part of the updated matrix.   Before  entry,
	      with  UPLO  = 'L' or 'l', the array AP must contain the lower triangular part of the symmetric matrix packed sequentially, column by
	      column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 ) and a( 3, 1 ) respectively, and so  on.  On  exit,
	      the  array AP is overwritten by the lower triangular part of the updated matrix.	Note that the imaginary parts of the diagonal ele-
	      ments need not be set, they are assumed to be zero, and on exit they are set to zero.

LAPACK version 3.0						   15 June 2000 							   CSPR(l)