BLAS/SRC/ssyr2.f(3)        Library Functions Manual        BLAS/SRC/ssyr2.f(3)

NAME
       BLAS/SRC/ssyr2.f

SYNOPSIS
   Functions/Subroutines
       subroutine ssyr2 (uplo, n, alpha, x, incx, y, incy, a, lda)
           SSYR2

Function/Subroutine Documentation
   subroutine ssyr2 (character uplo, integer n, real alpha, real, dimension(*)
       x, integer incx, real, dimension(*) y, integer incy, real,
       dimension(lda,*) a, integer lda)
       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, 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, 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, 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.

       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 146 of file ssyr2.f.

Author
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LAPACK                          Version 3.12.0             BLAS/SRC/ssyr2.f(3)