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).

SIDE

          SIDE is CHARACTER*1


          = 'L': apply Q or Q**H from the Left;


          = 'R': apply Q or Q**H from the Right.

TRANS

          TRANS is CHARACTER*1


          = 'N': apply Q  (No transpose)


          = 'C': apply Q**H (Conjugate transpose)

M

          M is INTEGER


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

N

          N is INTEGER


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

ILO

          ILO is INTEGER

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.

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.

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'.

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.

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.

LDC

          LDC is INTEGER


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

WORK

          WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))


          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

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.

INFO

          INFO is INTEGER


          = 0:  successful exit


          < 0:  if INFO = -i, the i-th argument had an illegal value

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December 2016