ssyr(l) [redhat man page]

SSYR(l) 							   BLAS routine 							   SSYR(l)

NAME

       SSYR - perform the symmetric rank 1 operation   A := alpha*x*x' + A,

SYNOPSIS

       SUBROUTINE SSYR ( UPLO, N, ALPHA, X, INCX, A, LDA )

	   REAL        ALPHA

	   INTEGER     INCX, LDA, N

	   CHARACTER*1 UPLO

	   REAL        A( LDA, * ), X( * )

PURPOSE

       SSYR   performs the symmetric rank 1 operation

       where alpha is a real scalar, x is an n element vector and A is an n by n symmetric matrix.

PARAMETERS

       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  - REAL		.
	      On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

       X      - REAL		 array of 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      - REAL		 array of 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  triangu-
	      lar  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.

	      Level 2 Blas routine.

	      -- Written on 22-October-1986.  Jack Dongarra, Argonne National Lab.  Jeremy Du Croz, Nag Central Office.  Sven Hammarling, Nag Cen-
	      tral Office.  Richard Hanson, Sandia National Labs.

BLAS routine							  16 October 1992							   SSYR(l)

DSYR(l) 							   BLAS routine 							   DSYR(l)

NAME

       DSYR - perform the symmetric rank 1 operation   A := alpha*x*x' + A,

SYNOPSIS

       SUBROUTINE DSYR ( UPLO, N, ALPHA, X, INCX, A, LDA )

	   DOUBLE      PRECISION ALPHA

	   INTEGER     INCX, LDA, N

	   CHARACTER*1 UPLO

	   DOUBLE      PRECISION A( LDA, * ), X( * )

PURPOSE

       DSYR   performs the symmetric rank 1 operation

       where alpha is a real scalar, x is an n element vector and A is an n by n symmetric matrix.

PARAMETERS

       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  - DOUBLE PRECISION.
	      On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

       X      - DOUBLE PRECISION array of 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      - DOUBLE PRECISION array of 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  triangu-
	      lar  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.

	      Level 2 Blas routine.

	      -- Written on 22-October-1986.  Jack Dongarra, Argonne National Lab.  Jeremy Du Croz, Nag Central Office.  Sven Hammarling, Nag Cen-
	      tral Office.  Richard Hanson, Sandia National Labs.

BLAS routine							  16 October 1992							   DSYR(l)