ESMF_DLARFX Subroutine

subroutine ESMF_DLARFX(SIDE, M, N, V, TAU, C, LDC, WORK)

\brief \b ESMF_DLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10. \htmlonly Download ESMF_DLARFX + dependencies [TGZ] [ZIP] [TXT] \endhtmlonly \par Purpose:

\verbatim

ESMF_DLARFX applies a real elementary reflector H to a real m by n matrix C, from either the left or the right. H is represented in the form

  H = I - tau * v * v**T

where tau is a real scalar and v is a real vector.

If tau = 0, then H is taken to be the unit matrix

This version uses inline code if H has order < 11. \endverbatim \param[in] SIDE \verbatim SIDE is CHARACTER*1 = ‘L’: form H * C = ‘R’: form C * H \endverbatim

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

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

\param[in] V \verbatim V is DOUBLE PRECISION array, dimension (M) if SIDE = ‘L’ or (N) if SIDE = ‘R’ The vector v in the representation of H. \endverbatim

\param[in] TAU \verbatim TAU is DOUBLE PRECISION The value tau in the representation of H. \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 the matrix H * C if SIDE = ‘L’, or C * H if SIDE = ‘R’. \endverbatim

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

\param[out] WORK \verbatim WORK is DOUBLE PRECISION array, dimension (N) if SIDE = ‘L’ or (M) if SIDE = ‘R’ WORK is not referenced if H has order < 11. \endverbatim \author Univ. of Tennessee \author Univ. of California Berkeley \author Univ. of Colorado Denver \author NAG Ltd. \date December 2016 \ingroup doubleOTHERauxiliary

Arguments