ESMF_DORML2 Subroutine

subroutine ESMF_DORML2(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, INFO)

\brief \b ESMF_DORML2 \htmlonly Download ESMF_DORML2 + dependencies [TGZ] [ZIP] [TXT] \endhtmlonly \par Purpose:

\verbatim

ESMF_DORML2 overwrites the general real m by n matrix C with

  Q * C  if SIDE = 'L' and TRANS = 'N', or

  Q**T* C  if SIDE = 'L' and TRANS = 'T', or

  C * Q  if SIDE = 'R' and TRANS = 'N', or

  C * Q**T if SIDE = 'R' and TRANS = 'T',

where Q is a real orthogonal matrix defined as the product of k elementary reflectors

  Q = H(k) . . . H(2) H(1)

as returned by ESMF_DGELQF. Q is of order m if SIDE = ‘L’ and of order n if SIDE = ‘R’. \endverbatim \param[in] SIDE \verbatim SIDE is CHARACTER1 = ‘L’: apply Q or QT from the Left = ‘R’: apply Q or Q*T from the Right \endverbatim

\param[in] TRANS \verbatim TRANS is CHARACTER1 = ‘N’: apply Q (No transpose) = ‘T’: apply Q*T (Transpose) \endverbatim

\param[in] M \verbatim M is INTEGER The number of rows of the matrix C. M >= 0. \endverbatim

\param[in] N \verbatim N is INTEGER The number of columns of the matrix C. N >= 0. \endverbatim

\param[in] K \verbatim K is INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = ‘L’, M >= K >= 0; if SIDE = ‘R’, N >= K >= 0. \endverbatim

\param[in] A \verbatim A is DOUBLE PRECISION array, dimension (LDA,M) if SIDE = ‘L’, (LDA,N) if SIDE = ‘R’ The i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,…,k, as returned by ESMF_DGELQF in the first k rows of its array argument A. A is modified by the routine but restored on exit. \endverbatim

\param[in] LDA \verbatim LDA is INTEGER The leading dimension of the array A. LDA >= max(1,K). \endverbatim

\param[in] TAU \verbatim TAU is DOUBLE PRECISION array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ESMF_DGELQF. \endverbatim

\param[in,out] C \verbatim C is DOUBLE PRECISION array, dimension (LDC,N) On entry, the m by n matrix C. On exit, C is overwritten by QC or QTC or CQT or CQ. \endverbatim

\param[in] LDC \verbatim LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). \endverbatim

\param[out] WORK \verbatim WORK is DOUBLE PRECISION array, dimension (N) if SIDE = ‘L’, (M) if SIDE = ‘R’ \endverbatim

\param[out] INFO \verbatim INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value \endverbatim \author Univ. of Tennessee \author Univ. of California Berkeley \author Univ. of Colorado Denver \author NAG Ltd. \date November 2011 \ingroup doubleOTHERcomputational

Arguments

Type IntentOptional Attributes Name
character(len=1) :: SIDE
character(len=1) :: TRANS
integer :: M
integer :: N
integer :: K
double precision :: A(LDA,*)
integer :: LDA
double precision :: TAU(*)
double precision :: C(LDC,*)
integer :: LDC
double precision :: WORK(*)
integer :: INFO