1CUNMTR(1)                LAPACK routine (version 3.1)                CUNMTR(1)
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NAME

6       CUNMTR  -  the general complex M-by-N matrix C with   SIDE = 'L' SIDE =
7       'R' TRANS = 'N'
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SYNOPSIS

10       SUBROUTINE CUNMTR( SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C, LDC,  WORK,
11                          LWORK, INFO )
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13           CHARACTER      SIDE, TRANS, UPLO
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15           INTEGER        INFO, LDA, LDC, LWORK, M, N
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17           COMPLEX        A( LDA, * ), C( LDC, * ), TAU( * ), WORK( * )
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PURPOSE

20       CUNMTR overwrites the general complex M-by-N matrix C with TRANS = 'C':
21       Q**H * C       C * Q**H
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23       where Q is a complex unitary matrix of order nq, with nq = m if SIDE  =
24       'L'  and nq = n if SIDE = 'R'. Q is defined as the product of nq-1 ele‐
25       mentary reflectors, as returned by CHETRD:
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27       if UPLO = 'U', Q = H(nq-1) . . . H(2) H(1);
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29       if UPLO = 'L', Q = H(1) H(2) . . . H(nq-1).
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ARGUMENTS

33       SIDE    (input) CHARACTER*1
34               = 'L': apply Q or Q**H from the Left;
35               = 'R': apply Q or Q**H from the Right.
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37       UPLO    (input) CHARACTER*1
38               = 'U': Upper triangle of A contains elementary reflectors  from
39               CHETRD;  = 'L': Lower triangle of A contains elementary reflec‐
40               tors from CHETRD.
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42       TRANS   (input) CHARACTER*1
43               = 'N':  No transpose, apply Q;
44               = 'C':  Conjugate transpose, apply Q**H.
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46       M       (input) INTEGER
47               The number of rows of the matrix C. M >= 0.
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49       N       (input) INTEGER
50               The number of columns of the matrix C. N >= 0.
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52       A       (input) COMPLEX array, dimension
53               (LDA,M) if SIDE = 'L' (LDA,N) if SIDE = 'R' The  vectors  which
54               define the elementary reflectors, as returned by CHETRD.
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56       LDA     (input) INTEGER
57               The  leading dimension of the array A.  LDA >= max(1,M) if SIDE
58               = 'L'; LDA >= max(1,N) if SIDE = 'R'.
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60       TAU     (input) COMPLEX array, dimension
61               (M-1) if SIDE = 'L' (N-1) if SIDE = 'R' TAU(i) must contain the
62               scalar  factor of the elementary reflector H(i), as returned by
63               CHETRD.
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65       C       (input/output) COMPLEX array, dimension (LDC,N)
66               On entry, the M-by-N matrix C.  On exit, C  is  overwritten  by
67               Q*C or Q**H*C or C*Q**H or C*Q.
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69       LDC     (input) INTEGER
70               The leading dimension of the array C. LDC >= max(1,M).
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72       WORK    (workspace/output) COMPLEX array, dimension (MAX(1,LWORK))
73               On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
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75       LWORK   (input) INTEGER
76               The  dimension  of  the  array  WORK.   If SIDE = 'L', LWORK >=
77               max(1,N); if SIDE = 'R', LWORK >= max(1,M).  For  optimum  per‐
78               formance  LWORK >= N*NB if SIDE = 'L', and LWORK >=M*NB if SIDE
79               = 'R', where NB is the optimal blocksize.
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81               If LWORK = -1, then a workspace query is assumed;  the  routine
82               only  calculates  the  optimal  size of the WORK array, returns
83               this value as the first entry of the WORK array, and  no  error
84               message related to LWORK is issued by XERBLA.
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86       INFO    (output) INTEGER
87               = 0:  successful exit
88               < 0:  if INFO = -i, the i-th argument had an illegal value
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92 LAPACK routine (version 3.1)    November 2006                       CUNMTR(1)
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