NAME¶

SGER - performs the rank 1 operation A := alpha*x*y' + A,

SYNOPSIS¶

SUBROUTINE SGER(M,N,ALPHA,X,INCX,Y,INCY,A,LDA)

REAL ALPHA INTEGER INCX,INCY,LDA,M,N REAL A(LDA,*),X(*),Y(*)

PURPOSE¶

SGER performs the rank 1 operation

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

ARGUMENTS¶

M - INTEGER.

On entry, M specifies the number of rows of the matrix A. M must be at least zero. Unchanged on exit.

N - INTEGER.

On entry, N specifies the number of columns 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 + ( m - 1 )*abs( INCX ) ). Before entry, the incremented array X must contain the m 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, the leading m by n part of the array A must contain the matrix of coefficients. On exit, A is overwritten by 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, m ). Unchanged on exit.

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.