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## zlarfy()

subroutine zlarfy | ( | character | uplo,
|  | integer | n,
|  | complex*16, dimension( * ) | v,
|  | integer | incv,
|  | complex*16 | tau,
|  | complex*16, dimension( ldc, * ) | c,
|  | integer | ldc,
|  | complex*16, dimension( * ) | work )

ZLARFY

Purpose:

      !>
      !> ZLARFY applies an elementary reflector, or Householder matrix, H,
      !> to an n x n Hermitian matrix C, from both the left and the right.
      !>
      !> H is represented in the form
      !>
      !>    H = I - tau * v * v'
      !>
      !> where  tau  is a scalar and  v  is a vector.
      !>
      !> If  tau  is  zero, then  H  is taken to be the unit matrix.
      !>

Parameters

  [in]

  UPLO

      !>          UPLO is CHARACTER*1
      !>          Specifies whether the upper or lower triangular part of the
      !>          Hermitian matrix C is stored.
      !>          = 'U':  Upper triangle
      !>          = 'L':  Lower triangle
      !>

  [in]

  N

      !>          N is INTEGER
      !>          The number of rows and columns of the matrix C.  N >= 0.
      !>

  [in]

  V

      !>          V is COMPLEX*16 array, dimension
      !>                  (1 + (N-1)*abs(INCV))
      !>          The vector v as described above.
      !>

  [in]

  INCV

      !>          INCV is INTEGER
      !>          The increment between successive elements of v.  INCV must
      !>          not be zero.
      !>

  [in]

  TAU

      !>          TAU is COMPLEX*16
      !>          The value tau as described above.
      !>

  [in,out]

  C

      !>          C is COMPLEX*16 array, dimension (LDC, N)
      !>          On entry, the matrix C.
      !>          On exit, C is overwritten by H * C * H'.
      !>

  [in]

  LDC

      !>          LDC is INTEGER
      !>          The leading dimension of the array C.  LDC >= max( 1, N ).
      !>

  [out]

  WORK

      !>          WORK is COMPLEX*16 array, dimension (N)
      !>

Author
  Univ. of Tennessee
  Univ. of California Berkeley
  Univ. of Colorado Denver
  NAG Ltd.