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zlarfx


 NAME
      ZLARFX - apply a complex elementary reflector H to a complex
      m by n matrix C, from either the left or the right

 SYNOPSIS
      SUBROUTINE ZLARFX( SIDE, M, N, V, TAU, C, LDC, WORK )

          CHARACTER      SIDE

          INTEGER        LDC, M, N

          COMPLEX*16     TAU

          COMPLEX*16     C( LDC, * ), V( * ), WORK( * )

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

            H = I - tau * v * v'

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

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

      This version uses inline code if H has order < 11.

 ARGUMENTS
      SIDE    (input) CHARACTER*1
              = 'L': form  H * C
              = 'R': form  C * H

      M       (input) INTEGER
              The number of rows of the matrix C.

      N       (input) INTEGER
              The number of columns of the matrix C.

      V       (input) COMPLEX*16 array, dimension (M) if SIDE = 'L'
              or (N) if SIDE = 'R' The vector v in the representa-
              tion of H.

      TAU     (input) COMPLEX*16
              The value tau in the representation of H.

      C       (input/output) COMPLEX*16 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'.

      LDC     (input) INTEGER
              The leading dimension of the array C. LDA >=
              max(1,M).

      WORK    (workspace) COMPLEX*16 array, dimension (N) if SIDE = 'L'
              or (M) if SIDE = 'R' WORK is not referenced if H has
              order < 11.