#include "ESMF_LapackBlas.inc" !> \brief \b DGER ! ! =========== DOCUMENTATION =========== ! ! Online html documentation available at ! http://www.netlib.org/lapack/explore-html/ ! ! Definition: ! =========== ! ! SUBROUTINE DGER(M,N,ALPHA,X,INCX,Y,INCY,A,LDA) ! ! .. Scalar Arguments .. ! DOUBLE PRECISION ALPHA ! INTEGER INCX,INCY,LDA,M,N ! .. ! .. Array Arguments .. ! DOUBLE PRECISION A(LDA,*),X(*),Y(*) ! .. ! ! !> \par Purpose: ! ============= !> !> \verbatim !> !> DGER performs the rank 1 operation !> !> A := alpha*x*y**T + A, !> !> 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. !> \endverbatim ! ! Arguments: ! ========== ! !> \param[in] M !> \verbatim !> M is INTEGER !> On entry, M specifies the number of rows of the matrix A. !> M must be at least zero. !> \endverbatim !> !> \param[in] N !> \verbatim !> N is INTEGER !> On entry, N specifies the number of columns of the matrix A. !> N must be at least zero. !> \endverbatim !> !> \param[in] ALPHA !> \verbatim !> ALPHA is DOUBLE PRECISION. !> On entry, ALPHA specifies the scalar alpha. !> \endverbatim !> !> \param[in] X !> \verbatim !> X is 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. !> \endverbatim !> !> \param[in] INCX !> \verbatim !> INCX is INTEGER !> On entry, INCX specifies the increment for the elements of !> X. INCX must not be zero. !> \endverbatim !> !> \param[in] Y !> \verbatim !> Y is 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. !> \endverbatim !> !> \param[in] INCY !> \verbatim !> INCY is INTEGER !> On entry, INCY specifies the increment for the elements of !> Y. INCY must not be zero. !> \endverbatim !> !> \param[in,out] A !> \verbatim !> A is 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. !> \endverbatim !> !> \param[in] LDA !> \verbatim !> 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, m ). !> \endverbatim ! ! Authors: ! ======== ! !> \author Univ. of Tennessee !> \author Univ. of California Berkeley !> \author Univ. of Colorado Denver !> \author NAG Ltd. ! !> \date November 2011 ! !> \ingroup double_blas_level2 ! !> \par Further Details: ! ===================== !> !> \verbatim !> !> 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. !> \endverbatim !> ! ===================================================================== SUBROUTINE DGER(M,N,ALPHA,X,INCX,Y,INCY,A,LDA) ! ! -- Reference BLAS level2 routine (version 3.4.0) -- ! -- Reference BLAS is a software package provided by Univ. of Tennessee, -- ! -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- ! November 2011 ! ! .. Scalar Arguments .. DOUBLE PRECISION ALPHA INTEGER INCX,INCY,LDA,M,N ! .. ! .. Array Arguments .. DOUBLE PRECISION A(LDA,*),X(*),Y(*) ! .. ! ! ===================================================================== ! ! .. Parameters .. DOUBLE PRECISION ZERO PARAMETER (ZERO=0.0D+0) ! .. ! .. Local Scalars .. DOUBLE PRECISION TEMP INTEGER I,INFO,IX,J,JY,KX ! .. ! .. External Subroutines .. EXTERNAL XERBLA ! .. ! .. Intrinsic Functions .. INTRINSIC MAX ! .. ! ! Test the input parameters. ! INFO = 0 IF (M.LT.0) THEN INFO = 1 ELSE IF (N.LT.0) THEN INFO = 2 ELSE IF (INCX.EQ.0) THEN INFO = 5 ELSE IF (INCY.EQ.0) THEN INFO = 7 ELSE IF (LDA.LT.MAX(1,M)) THEN INFO = 9 END IF IF (INFO.NE.0) THEN CALL XERBLA('DGER ',INFO) RETURN END IF ! ! Quick return if possible. ! IF ((M.EQ.0) .OR. (N.EQ.0) .OR. (ALPHA.EQ.ZERO)) RETURN ! ! Start the operations. In this version the elements of A are ! accessed sequentially with one pass through A. ! IF (INCY.GT.0) THEN JY = 1 ELSE JY = 1 - (N-1)*INCY END IF IF (INCX.EQ.1) THEN DO 20 J = 1,N IF (Y(JY).NE.ZERO) THEN TEMP = ALPHA*Y(JY) DO 10 I = 1,M A(I,J) = A(I,J) + X(I)*TEMP 10 CONTINUE END IF JY = JY + INCY 20 CONTINUE ELSE IF (INCX.GT.0) THEN KX = 1 ELSE KX = 1 - (M-1)*INCX END IF DO 40 J = 1,N IF (Y(JY).NE.ZERO) THEN TEMP = ALPHA*Y(JY) IX = KX DO 30 I = 1,M A(I,J) = A(I,J) + X(IX)*TEMP IX = IX + INCX 30 CONTINUE END IF JY = JY + INCY 40 CONTINUE END IF ! RETURN ! ! End of DGER . ! END