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## zunmlq()

subroutine zunmlq | ( | character | side,
|  | character | trans,
|  | integer | m,
|  | integer | n,
|  | integer | k,
|  | 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 )

ZUNMLQ

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

Purpose:

      !>
      !> ZUNMLQ 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 defined as the product of k
      !> elementary reflectors
      !>
      !>       Q = H(k)**H . . . H(2)**H H(1)**H
      !>
      !> as returned by ZGELQF. Q is of order M if SIDE = 'L' and of order N
      !> if SIDE = 'R'.
      !>

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':  No transpose, apply Q;
      !>          = 'C':  Conjugate transpose, apply Q**H.
      !>

  [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]

  K

      !>          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.
      !>

  [in]

  A

      !>          A is COMPLEX*16 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
      !>          ZGELQF in the first k rows of its array argument A.
      !>

  [in]

  LDA

      !>          LDA is INTEGER
      !>          The leading dimension of the array A. LDA >= max(1,K).
      !>

  [in]

  TAU

      !>          TAU is COMPLEX*16 array, dimension (K)
      !>          TAU(i) must contain the scalar factor of the elementary
      !>          reflector H(i), as returned by ZGELQF.
      !>

  [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 good performance, LWORK should generally be larger.
      !>
      !>          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.