dger

DGER(1)                          BLAS routine                          DGER(1)



NAME
       DGER - performs the rank 1 operation   A := alpha*x*y' + 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.




BLAS routine                     November 2008                         DGER(1)