dger (l) - Linux Manuals

dger: performs the rank 1 operation A := alpha*x*yaq + A,

NAME

DGER - performs the rank 1 operation A := alpha*x*yaq + A,

SYNOPSIS

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

    
DOUBLE PRECISION ALPHA

    
INTEGER INCX,INCY,LDA,M,N

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

PURPOSE

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