Contents


NAME

     cunmlq - overwrite the general complex M-by-N matrix C  with
     SIDE = 'L' SIDE = 'R' TRANS = 'N'

SYNOPSIS

     SUBROUTINE CUNMLQ(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK,
           LWORK, INFO)

     CHARACTER * 1 SIDE, TRANS
     COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
     INTEGER M, N, K, LDA, LDC, LWORK, INFO

     SUBROUTINE CUNMLQ_64(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK,
           LWORK, INFO)

     CHARACTER * 1 SIDE, TRANS
     COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
     INTEGER*8 M, N, K, LDA, LDC, LWORK, INFO

  F95 INTERFACE
     SUBROUTINE UNMLQ(SIDE, [TRANS], [M], [N], [K], A, [LDA], TAU, C, [LDC],
            [WORK], [LWORK], [INFO])

     CHARACTER(LEN=1) :: SIDE, TRANS
     COMPLEX, DIMENSION(:) :: TAU, WORK
     COMPLEX, DIMENSION(:,:) :: A, C
     INTEGER :: M, N, K, LDA, LDC, LWORK, INFO

     SUBROUTINE UNMLQ_64(SIDE, [TRANS], [M], [N], [K], A, [LDA], TAU, C,
            [LDC], [WORK], [LWORK], [INFO])

     CHARACTER(LEN=1) :: SIDE, TRANS
     COMPLEX, DIMENSION(:) :: TAU, WORK
     COMPLEX, DIMENSION(:,:) :: A, C
     INTEGER(8) :: M, N, K, LDA, LDC, LWORK, INFO

  C INTERFACE
     #include <sunperf.h>

     void cunmlq(char side, char trans, int m, int n, int k, com-
               plex  *a,  int  lda, complex *tau, complex *c, int
               ldc, int *info);

     void cunmlq_64(char side, char trans, long m, long  n,  long
               k, complex *a, long lda, complex *tau, complex *c,
               long ldc, long *info);

PURPOSE

     cunmlq overwrites the general complex M-by-N matrix  C  with
     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(2)' H(1)'

     as returned by CGELQF. Q is of order M if SIDE = 'L' and  of
     order N if SIDE = 'R'.

ARGUMENTS

     SIDE (input)
               = 'L': apply Q or Q**H from the Left;
               = 'R': apply Q or Q**H from the Right.

     TRANS (input)
               = 'N':  No transpose, apply Q;
               = 'C':  Conjugate transpose, apply Q**H.

               TRANS is defaulted to 'N' for F95 INTERFACE.

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

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

     K (input) The number of elementary reflectors whose  product
               defines the matrix Q.  If SIDE = 'L', M >= K >= 0;
               if SIDE = 'R', N >= K >= 0.

     A (input) (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  CGELQF  in  the  first k rows of its
               array argument A.  A is modified  by  the  routine
               but restored on exit.

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

     TAU (input)
               TAU(i) must contain the scalar factor of the  ele-
               mentary reflector H(i), as returned by CGELQF.

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

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

     LWORK (input)
               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 (output)
               = 0:  successful exit
               < 0:  if INFO = -i, the i-th argument had an ille-
               gal value