Provided by: libblas-doc_1.2.20110419-7_all 
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 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 - 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 Central Office. Richard Hanson, Sandia National Labs.