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ssyr2(3) [centos man page]

ssyr2.f(3)							      LAPACK								ssyr2.f(3)

NAME

       ssyr2.f -

SYNOPSIS

   Functions/Subroutines
       subroutine ssyr2 (UPLO, N, ALPHA, X, INCX, Y, INCY, A, LDA)
	   SSYR2

Function/Subroutine Documentation
   subroutine ssyr2 (characterUPLO, integerN, realALPHA, real, dimension(*)X, integerINCX, real, dimension(*)Y, integerINCY, real,
       dimension(lda,*)A, integerLDA)
       SSYR2 Purpose:

	    SSYR2  performs the symmetric rank 2 operation

	       A := alpha*x*y**T + alpha*y*x**T + A,

	    where alpha is a scalar, x and y are n element vectors and A is an n
	    by n symmetric matrix.

       Parameters:
	   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.

	   N

		     N is INTEGER
		      On entry, N specifies the order of the matrix A.
		      N must be at least zero.

	   ALPHA

		     ALPHA is REAL
		      On entry, ALPHA specifies the scalar alpha.

	   X

		     X is REAL array of dimension at least
		      ( 1 + ( n - 1 )*abs( INCX ) ).
		      Before entry, the incremented array X must contain the n
		      element vector x.

	   INCX

		     INCX is INTEGER
		      On entry, INCX specifies the increment for the elements of
		      X. INCX must not be zero.

	   Y

		     Y is REAL array of dimension at least
		      ( 1 + ( n - 1 )*abs( INCY ) ).
		      Before entry, the incremented array Y must contain the n
		      element vector y.

	   INCY

		     INCY is INTEGER
		      On entry, INCY specifies the increment for the elements of
		      Y. INCY must not be zero.

	   A

		     A is 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 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 ).

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Further Details:

	     Level 2 Blas routine.

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

       Definition at line 148 of file ssyr2.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012							ssyr2.f(3)

Check Out this Related Man Page

SSYR2(l)							   BLAS routine 							  SSYR2(l)

NAME

       SSYR2 - perform the symmetric rank 2 operation	A := alpha*x*y' + alpha*y*x' + A,

SYNOPSIS

       SUBROUTINE SSYR2 ( UPLO, N, ALPHA, X, INCX, Y, INCY, A, LDA )

	   REAL 	ALPHA

	   INTEGER	INCX, INCY, LDA, N

	   CHARACTER*1	UPLO

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

PURPOSE

       SSYR2  performs the symmetric rank 2 operation

       where alpha is a scalar, x and y are n element vectors 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.

       Y      - REAL		 array of dimension at least
	      ( 1 + ( n - 1 )*abs( INCY ) ).  Before entry, the incremented array Y must contain the n element vector y.  Unchanged on exit.

       INCY   - INTEGER.
	      On entry, INCY specifies the increment for the elements of Y. INCY 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							  SSYR2(l)
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