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## zunmhr()

subroutine zunmhr | ( | character | side,
|  | character | trans,
|  | integer | m,
|  | integer | n,
|  | integer | ilo,
|  | integer | ihi,
|  | complex*16, dimension( lda, * ) | a,
|  | integer | lda,
|  | complex*16, dimension( * ) | tau,
|  | complex*16, dimension( ldc, * ) | c,
|  | integer | ldc,
|  | complex*16, dimension( * ) | work,
|  | integer | lwork,
|  | integer | info )

ZUNMHR

Download ZUNMHR + dependencies [TGZ] [ZIP] [TXT]

Purpose:

      !>
      !> ZUNMHR overwrites the general complex M-by-N matrix C with
      !>
      !>                 SIDE = 'L'     SIDE = 'R'
      !> TRANS = 'N':      Q * C          C * Q
      !> TRANS = 'C':      Q**H * C       C * Q**H
      !>
      !> where Q is a complex unitary matrix of order nq, with nq = m if
      !> SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the product of
      !> IHI-ILO elementary reflectors, as returned by ZGEHRD:
      !>
      !> Q = H(ilo) H(ilo+1) . . . H(ihi-1).
      !>

Parameters

  [in]

  SIDE

      !>          SIDE is CHARACTER*1
      !>          = 'L': apply Q or Q**H from the Left;
      !>          = 'R': apply Q or Q**H from the Right.
      !>

  [in]

  TRANS

      !>          TRANS is CHARACTER*1
      !>          = 'N': apply Q  (No transpose)
      !>          = 'C': apply Q**H (Conjugate transpose)
      !>

  [in]

  M

      !>          M is INTEGER
      !>          The number of rows of the matrix C. M >= 0.
      !>

  [in]

  N

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

  [in]

  ILO

      !>          ILO is INTEGER
      !>

  [in]

  IHI

      !>          IHI is INTEGER
      !>
      !>          ILO and IHI must have the same values as in the previous call
      !>          of ZGEHRD. Q is equal to the unit matrix except in the
      !>          submatrix Q(ilo+1:ihi,ilo+1:ihi).
      !>          If SIDE = 'L', then 1 <= ILO <= IHI <= M, if M > 0, and
      !>          ILO = 1 and IHI = 0, if M = 0;
      !>          if SIDE = 'R', then 1 <= ILO <= IHI <= N, if N > 0, and
      !>          ILO = 1 and IHI = 0, if N = 0.
      !>

  [in]

  A

      !>          A is COMPLEX*16 array, dimension
      !>                               (LDA,M) if SIDE = 'L'
      !>                               (LDA,N) if SIDE = 'R'
      !>          The vectors which define the elementary reflectors, as
      !>          returned by ZGEHRD.
      !>

  [in]

  LDA

      !>          LDA is INTEGER
      !>          The leading dimension of the array A.
      !>          LDA >= max(1,M) if SIDE = 'L'; LDA >= max(1,N) if SIDE = 'R'.
      !>

  [in]

  TAU

      !>          TAU is COMPLEX*16 array, dimension
      !>                               (M-1) if SIDE = 'L'
      !>                               (N-1) if SIDE = 'R'
      !>          TAU(i) must contain the scalar factor of the elementary
      !>          reflector H(i), as returned by ZGEHRD.
      !>

  [in,out]

  C

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

  [in]

  LDC

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

  [out]

  WORK

      !>          WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
      !>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
      !>

  [in]

  LWORK

      !>          LWORK is INTEGER
      !>          The dimension of the array WORK.
      !>          If SIDE = 'L', LWORK >= max(1,N);
      !>          if SIDE = 'R', LWORK >= max(1,M).
      !>          For optimum performance LWORK >= N*NB if SIDE = 'L', and
      !>          LWORK >= M*NB if SIDE = 'R', where NB is the optimal
      !>          blocksize.
      !>
      !>          If LWORK = -1, then a workspace query is assumed; the routine
      !>          only calculates the optimal size of the WORK array, returns
      !>          this value as the first entry of the WORK array, and no error
      !>          message related to LWORK is issued by XERBLA.
      !>

  [out]

  INFO

      !>          INFO is INTEGER
      !>          = 0:  successful exit
      !>          < 0:  if INFO = -i, the i-th argument had an illegal value
      !>

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