コード例 #1
0
/* Subroutine */ int zggsvp_(char *jobu, char *jobv, char *jobq, integer *m, 
	integer *p, integer *n, doublecomplex *a, integer *lda, doublecomplex 
	*b, integer *ldb, doublereal *tola, doublereal *tolb, integer *k, 
	integer *l, doublecomplex *u, integer *ldu, doublecomplex *v, integer 
	*ldv, doublecomplex *q, integer *ldq, integer *iwork, doublereal *
	rwork, doublecomplex *tau, doublecomplex *work, integer *info)
{
/*  -- LAPACK routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       September 30, 1994   


    Purpose   
    =======   

    ZGGSVP computes unitary matrices U, V and Q such that   

                     N-K-L  K    L   
     U'*A*Q =     K ( 0    A12  A13 )  if M-K-L >= 0;   
                  L ( 0     0   A23 )   
              M-K-L ( 0     0    0  )   

                     N-K-L  K    L   
            =     K ( 0    A12  A13 )  if M-K-L < 0;   
                M-K ( 0     0   A23 )   

                   N-K-L  K    L   
     V'*B*Q =   L ( 0     0   B13 )   
              P-L ( 0     0    0  )   

    where the K-by-K matrix A12 and L-by-L matrix B13 are nonsingular   
    upper triangular; A23 is L-by-L upper triangular if M-K-L >= 0,   
    otherwise A23 is (M-K)-by-L upper trapezoidal.  K+L = the effective   
    numerical rank of the (M+P)-by-N matrix (A',B')'.  Z' denotes the   
    conjugate transpose of Z.   

    This decomposition is the preprocessing step for computing the   
    Generalized Singular Value Decomposition (GSVD), see subroutine   
    ZGGSVD.   

    Arguments   
    =========   

    JOBU    (input) CHARACTER*1   
            = 'U':  Unitary matrix U is computed;   
            = 'N':  U is not computed.   

    JOBV    (input) CHARACTER*1   
            = 'V':  Unitary matrix V is computed;   
            = 'N':  V is not computed.   

    JOBQ    (input) CHARACTER*1   
            = 'Q':  Unitary matrix Q is computed;   
            = 'N':  Q is not computed.   

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

    P       (input) INTEGER   
            The number of rows of the matrix B.  P >= 0.   

    N       (input) INTEGER   
            The number of columns of the matrices A and B.  N >= 0.   

    A       (input/output) COMPLEX*16 array, dimension (LDA,N)   
            On entry, the M-by-N matrix A.   
            On exit, A contains the triangular (or trapezoidal) matrix   
            described in the Purpose section.   

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

    B       (input/output) COMPLEX*16 array, dimension (LDB,N)   
            On entry, the P-by-N matrix B.   
            On exit, B contains the triangular matrix described in   
            the Purpose section.   

    LDB     (input) INTEGER   
            The leading dimension of the array B. LDB >= max(1,P).   

    TOLA    (input) DOUBLE PRECISION   
    TOLB    (input) DOUBLE PRECISION   
            TOLA and TOLB are the thresholds to determine the effective   
            numerical rank of matrix B and a subblock of A. Generally,   
            they are set to   
               TOLA = MAX(M,N)*norm(A)*MAZHEPS,   
               TOLB = MAX(P,N)*norm(B)*MAZHEPS.   
            The size of TOLA and TOLB may affect the size of backward   
            errors of the decomposition.   

    K       (output) INTEGER   
    L       (output) INTEGER   
            On exit, K and L specify the dimension of the subblocks   
            described in Purpose section.   
            K + L = effective numerical rank of (A',B')'.   

    U       (output) COMPLEX*16 array, dimension (LDU,M)   
            If JOBU = 'U', U contains the unitary matrix U.   
            If JOBU = 'N', U is not referenced.   

    LDU     (input) INTEGER   
            The leading dimension of the array U. LDU >= max(1,M) if   
            JOBU = 'U'; LDU >= 1 otherwise.   

    V       (output) COMPLEX*16 array, dimension (LDV,M)   
            If JOBV = 'V', V contains the unitary matrix V.   
            If JOBV = 'N', V is not referenced.   

    LDV     (input) INTEGER   
            The leading dimension of the array V. LDV >= max(1,P) if   
            JOBV = 'V'; LDV >= 1 otherwise.   

    Q       (output) COMPLEX*16 array, dimension (LDQ,N)   
            If JOBQ = 'Q', Q contains the unitary matrix Q.   
            If JOBQ = 'N', Q is not referenced.   

    LDQ     (input) INTEGER   
            The leading dimension of the array Q. LDQ >= max(1,N) if   
            JOBQ = 'Q'; LDQ >= 1 otherwise.   

    IWORK   (workspace) INTEGER array, dimension (N)   

    RWORK   (workspace) DOUBLE PRECISION array, dimension (2*N)   

    TAU     (workspace) COMPLEX*16 array, dimension (N)   

    WORK    (workspace) COMPLEX*16 array, dimension (max(3*N,M,P))   

    INFO    (output) INTEGER   
            = 0:  successful exit   
            < 0:  if INFO = -i, the i-th argument had an illegal value.   

    Further Details   
    ===============   

    The subroutine uses LAPACK subroutine ZGEQPF for the QR factorization   
    with column pivoting to detect the effective numerical rank of the   
    a matrix. It may be replaced by a better rank determination strategy.   

    =====================================================================   


       Test the input parameters   

       Parameter adjustments */
    /* Table of constant values */
    static doublecomplex c_b1 = {0.,0.};
    static doublecomplex c_b2 = {1.,0.};
    
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, q_dim1, q_offset, u_dim1, 
	    u_offset, v_dim1, v_offset, i__1, i__2, i__3;
    doublereal d__1, d__2;
    /* Builtin functions */
    double d_imag(doublecomplex *);
    /* Local variables */
    static integer i__, j;
    extern logical lsame_(char *, char *);
    static logical wantq, wantu, wantv;
    extern /* Subroutine */ int zgeqr2_(integer *, integer *, doublecomplex *,
	     integer *, doublecomplex *, doublecomplex *, integer *), zgerq2_(
	    integer *, integer *, doublecomplex *, integer *, doublecomplex *,
	     doublecomplex *, integer *), zung2r_(integer *, integer *, 
	    integer *, doublecomplex *, integer *, doublecomplex *, 
	    doublecomplex *, integer *), zunm2r_(char *, char *, integer *, 
	    integer *, integer *, doublecomplex *, integer *, doublecomplex *,
	     doublecomplex *, integer *, doublecomplex *, integer *), zunmr2_(char *, char *, integer *, integer *, integer *, 
	    doublecomplex *, integer *, doublecomplex *, doublecomplex *, 
	    integer *, doublecomplex *, integer *), xerbla_(
	    char *, integer *), zgeqpf_(integer *, integer *, 
	    doublecomplex *, integer *, integer *, doublecomplex *, 
	    doublecomplex *, doublereal *, integer *), zlacpy_(char *, 
	    integer *, integer *, doublecomplex *, integer *, doublecomplex *,
	     integer *);
    static logical forwrd;
    extern /* Subroutine */ int zlaset_(char *, integer *, integer *, 
	    doublecomplex *, doublecomplex *, doublecomplex *, integer *), zlapmt_(logical *, integer *, integer *, doublecomplex *,
	     integer *, integer *);
#define a_subscr(a_1,a_2) (a_2)*a_dim1 + a_1
#define a_ref(a_1,a_2) a[a_subscr(a_1,a_2)]
#define b_subscr(a_1,a_2) (a_2)*b_dim1 + a_1
#define b_ref(a_1,a_2) b[b_subscr(a_1,a_2)]
#define u_subscr(a_1,a_2) (a_2)*u_dim1 + a_1
#define u_ref(a_1,a_2) u[u_subscr(a_1,a_2)]
#define v_subscr(a_1,a_2) (a_2)*v_dim1 + a_1
#define v_ref(a_1,a_2) v[v_subscr(a_1,a_2)]


    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1 * 1;
    b -= b_offset;
    u_dim1 = *ldu;
    u_offset = 1 + u_dim1 * 1;
    u -= u_offset;
    v_dim1 = *ldv;
    v_offset = 1 + v_dim1 * 1;
    v -= v_offset;
    q_dim1 = *ldq;
    q_offset = 1 + q_dim1 * 1;
    q -= q_offset;
    --iwork;
    --rwork;
    --tau;
    --work;

    /* Function Body */
    wantu = lsame_(jobu, "U");
    wantv = lsame_(jobv, "V");
    wantq = lsame_(jobq, "Q");
    forwrd = TRUE_;

    *info = 0;
    if (! (wantu || lsame_(jobu, "N"))) {
	*info = -1;
    } else if (! (wantv || lsame_(jobv, "N"))) {
	*info = -2;
    } else if (! (wantq || lsame_(jobq, "N"))) {
	*info = -3;
    } else if (*m < 0) {
	*info = -4;
    } else if (*p < 0) {
	*info = -5;
    } else if (*n < 0) {
	*info = -6;
    } else if (*lda < max(1,*m)) {
	*info = -8;
    } else if (*ldb < max(1,*p)) {
	*info = -10;
    } else if (*ldu < 1 || wantu && *ldu < *m) {
	*info = -16;
    } else if (*ldv < 1 || wantv && *ldv < *p) {
	*info = -18;
    } else if (*ldq < 1 || wantq && *ldq < *n) {
	*info = -20;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("ZGGSVP", &i__1);
	return 0;
    }

/*     QR with column pivoting of B: B*P = V*( S11 S12 )   
                                             (  0   0  ) */

    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	iwork[i__] = 0;
/* L10: */
    }
    zgeqpf_(p, n, &b[b_offset], ldb, &iwork[1], &tau[1], &work[1], &rwork[1], 
	    info);

/*     Update A := A*P */

    zlapmt_(&forwrd, m, n, &a[a_offset], lda, &iwork[1]);

/*     Determine the effective rank of matrix B. */

    *l = 0;
    i__1 = min(*p,*n);
    for (i__ = 1; i__ <= i__1; ++i__) {
	i__2 = b_subscr(i__, i__);
	if ((d__1 = b[i__2].r, abs(d__1)) + (d__2 = d_imag(&b_ref(i__, i__)), 
		abs(d__2)) > *tolb) {
	    ++(*l);
	}
/* L20: */
    }

    if (wantv) {

/*        Copy the details of V, and form V. */

	zlaset_("Full", p, p, &c_b1, &c_b1, &v[v_offset], ldv);
	if (*p > 1) {
	    i__1 = *p - 1;
	    zlacpy_("Lower", &i__1, n, &b_ref(2, 1), ldb, &v_ref(2, 1), ldv);
	}
	i__1 = min(*p,*n);
	zung2r_(p, p, &i__1, &v[v_offset], ldv, &tau[1], &work[1], info);
    }

/*     Clean up B */

    i__1 = *l - 1;
    for (j = 1; j <= i__1; ++j) {
	i__2 = *l;
	for (i__ = j + 1; i__ <= i__2; ++i__) {
	    i__3 = b_subscr(i__, j);
	    b[i__3].r = 0., b[i__3].i = 0.;
/* L30: */
	}
/* L40: */
    }
    if (*p > *l) {
	i__1 = *p - *l;
	zlaset_("Full", &i__1, n, &c_b1, &c_b1, &b_ref(*l + 1, 1), ldb);
    }

    if (wantq) {

/*        Set Q = I and Update Q := Q*P */

	zlaset_("Full", n, n, &c_b1, &c_b2, &q[q_offset], ldq);
	zlapmt_(&forwrd, n, n, &q[q_offset], ldq, &iwork[1]);
    }

    if (*p >= *l && *n != *l) {

/*        RQ factorization of ( S11 S12 ) = ( 0 S12 )*Z */

	zgerq2_(l, n, &b[b_offset], ldb, &tau[1], &work[1], info);

/*        Update A := A*Z' */

	zunmr2_("Right", "Conjugate transpose", m, n, l, &b[b_offset], ldb, &
		tau[1], &a[a_offset], lda, &work[1], info);
	if (wantq) {

/*           Update Q := Q*Z' */

	    zunmr2_("Right", "Conjugate transpose", n, n, l, &b[b_offset], 
		    ldb, &tau[1], &q[q_offset], ldq, &work[1], info);
	}

/*        Clean up B */

	i__1 = *n - *l;
	zlaset_("Full", l, &i__1, &c_b1, &c_b1, &b[b_offset], ldb);
	i__1 = *n;
	for (j = *n - *l + 1; j <= i__1; ++j) {
	    i__2 = *l;
	    for (i__ = j - *n + *l + 1; i__ <= i__2; ++i__) {
		i__3 = b_subscr(i__, j);
		b[i__3].r = 0., b[i__3].i = 0.;
/* L50: */
	    }
/* L60: */
	}

    }

/*     Let              N-L     L   
                  A = ( A11    A12 ) M,   

       then the following does the complete QR decomposition of A11:   

                A11 = U*(  0  T12 )*P1'   
                        (  0   0  ) */

    i__1 = *n - *l;
    for (i__ = 1; i__ <= i__1; ++i__) {
	iwork[i__] = 0;
/* L70: */
    }
    i__1 = *n - *l;
    zgeqpf_(m, &i__1, &a[a_offset], lda, &iwork[1], &tau[1], &work[1], &rwork[
	    1], info);

/*     Determine the effective rank of A11 */

    *k = 0;
/* Computing MIN */
    i__2 = *m, i__3 = *n - *l;
    i__1 = min(i__2,i__3);
    for (i__ = 1; i__ <= i__1; ++i__) {
	i__2 = a_subscr(i__, i__);
	if ((d__1 = a[i__2].r, abs(d__1)) + (d__2 = d_imag(&a_ref(i__, i__)), 
		abs(d__2)) > *tola) {
	    ++(*k);
	}
/* L80: */
    }

/*     Update A12 := U'*A12, where A12 = A( 1:M, N-L+1:N )   

   Computing MIN */
    i__2 = *m, i__3 = *n - *l;
    i__1 = min(i__2,i__3);
    zunm2r_("Left", "Conjugate transpose", m, l, &i__1, &a[a_offset], lda, &
	    tau[1], &a_ref(1, *n - *l + 1), lda, &work[1], info);

    if (wantu) {

/*        Copy the details of U, and form U */

	zlaset_("Full", m, m, &c_b1, &c_b1, &u[u_offset], ldu);
	if (*m > 1) {
	    i__1 = *m - 1;
	    i__2 = *n - *l;
	    zlacpy_("Lower", &i__1, &i__2, &a_ref(2, 1), lda, &u_ref(2, 1), 
		    ldu);
	}
/* Computing MIN */
	i__2 = *m, i__3 = *n - *l;
	i__1 = min(i__2,i__3);
	zung2r_(m, m, &i__1, &u[u_offset], ldu, &tau[1], &work[1], info);
    }

    if (wantq) {

/*        Update Q( 1:N, 1:N-L )  = Q( 1:N, 1:N-L )*P1 */

	i__1 = *n - *l;
	zlapmt_(&forwrd, n, &i__1, &q[q_offset], ldq, &iwork[1]);
    }

/*     Clean up A: set the strictly lower triangular part of   
       A(1:K, 1:K) = 0, and A( K+1:M, 1:N-L ) = 0. */

    i__1 = *k - 1;
    for (j = 1; j <= i__1; ++j) {
	i__2 = *k;
	for (i__ = j + 1; i__ <= i__2; ++i__) {
	    i__3 = a_subscr(i__, j);
	    a[i__3].r = 0., a[i__3].i = 0.;
/* L90: */
	}
/* L100: */
    }
    if (*m > *k) {
	i__1 = *m - *k;
	i__2 = *n - *l;
	zlaset_("Full", &i__1, &i__2, &c_b1, &c_b1, &a_ref(*k + 1, 1), lda);
    }

    if (*n - *l > *k) {

/*        RQ factorization of ( T11 T12 ) = ( 0 T12 )*Z1 */

	i__1 = *n - *l;
	zgerq2_(k, &i__1, &a[a_offset], lda, &tau[1], &work[1], info);

	if (wantq) {

/*           Update Q( 1:N,1:N-L ) = Q( 1:N,1:N-L )*Z1' */

	    i__1 = *n - *l;
	    zunmr2_("Right", "Conjugate transpose", n, &i__1, k, &a[a_offset],
		     lda, &tau[1], &q[q_offset], ldq, &work[1], info);
	}

/*        Clean up A */

	i__1 = *n - *l - *k;
	zlaset_("Full", k, &i__1, &c_b1, &c_b1, &a[a_offset], lda);
	i__1 = *n - *l;
	for (j = *n - *l - *k + 1; j <= i__1; ++j) {
	    i__2 = *k;
	    for (i__ = j - *n + *l + *k + 1; i__ <= i__2; ++i__) {
		i__3 = a_subscr(i__, j);
		a[i__3].r = 0., a[i__3].i = 0.;
/* L110: */
	    }
/* L120: */
	}

    }

    if (*m > *k) {

/*        QR factorization of A( K+1:M,N-L+1:N ) */

	i__1 = *m - *k;
	zgeqr2_(&i__1, l, &a_ref(*k + 1, *n - *l + 1), lda, &tau[1], &work[1],
		 info);

	if (wantu) {

/*           Update U(:,K+1:M) := U(:,K+1:M)*U1 */

	    i__1 = *m - *k;
/* Computing MIN */
	    i__3 = *m - *k;
	    i__2 = min(i__3,*l);
	    zunm2r_("Right", "No transpose", m, &i__1, &i__2, &a_ref(*k + 1, *
		    n - *l + 1), lda, &tau[1], &u_ref(1, *k + 1), ldu, &work[
		    1], info);
	}

/*        Clean up */

	i__1 = *n;
	for (j = *n - *l + 1; j <= i__1; ++j) {
	    i__2 = *m;
	    for (i__ = j - *n + *k + *l + 1; i__ <= i__2; ++i__) {
		i__3 = a_subscr(i__, j);
		a[i__3].r = 0., a[i__3].i = 0.;
/* L130: */
	    }
/* L140: */
	}

    }

    return 0;

/*     End of ZGGSVP */

} /* zggsvp_ */
コード例 #2
0
ファイル: zunmrq.c プロジェクト: dacap/loseface
/* Subroutine */ int zunmrq_(char *side, char *trans, integer *m, integer *n, 
	integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, 
	doublecomplex *c__, integer *ldc, doublecomplex *work, integer *lwork, 
	 integer *info)
{
    /* System generated locals */
    address a__1[2];
    integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3[2], i__4, 
	    i__5;
    char ch__1[2];

    /* Builtin functions */
    /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen);

    /* Local variables */
    integer i__;
    doublecomplex t[4160]	/* was [65][64] */;
    integer i1, i2, i3, ib, nb, mi, ni, nq, nw, iws;
    logical left;
    extern logical lsame_(char *, char *);
    integer nbmin, iinfo;
    extern /* Subroutine */ int zunmr2_(char *, char *, integer *, integer *, 
	    integer *, doublecomplex *, integer *, doublecomplex *, 
	    doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *);
    extern integer ilaenv_(integer *, char *, char *, integer *, integer *, 
	    integer *, integer *);
    extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, 
	    integer *, integer *, integer *, doublecomplex *, integer *, 
	    doublecomplex *, integer *, doublecomplex *, integer *, 
	    doublecomplex *, integer *);
    logical notran;
    integer ldwork;
    extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *, 
	    doublecomplex *, integer *, doublecomplex *, doublecomplex *, 
	    integer *);
    char transt[1];
    integer lwkopt;
    logical lquery;


/*  -- LAPACK routine (version 3.1) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  ZUNMRQ 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(1)' H(2)' . . . H(k)' */

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

/*  Arguments */
/*  ========= */

/*  SIDE    (input) CHARACTER*1 */
/*          = 'L': apply Q or Q**H from the Left; */
/*          = 'R': apply Q or Q**H from the Right. */

/*  TRANS   (input) CHARACTER*1 */
/*          = 'N':  No transpose, apply Q; */
/*          = 'C':  Transpose, apply Q**H. */

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

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

/*  K       (input) INTEGER */
/*          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) 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 */
/*          ZGERQF in the last k rows of its array argument A. */
/*          A is modified by the routine but restored on exit. */

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

/*  TAU     (input) COMPLEX*16 array, dimension (K) */
/*          TAU(i) must contain the scalar factor of the elementary */
/*          reflector H(i), as returned by ZGERQF. */

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

/*  WORK    (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) */
/*          On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */

/*  LWORK   (input) 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    (output) INTEGER */
/*          = 0:  successful exit */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. Local Arrays .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    c_dim1 = *ldc;
    c_offset = 1 + c_dim1;
    c__ -= c_offset;
    --work;

    /* Function Body */
    *info = 0;
    left = lsame_(side, "L");
    notran = lsame_(trans, "N");
    lquery = *lwork == -1;

/*     NQ is the order of Q and NW is the minimum dimension of WORK */

    if (left) {
	nq = *m;
	nw = max(1,*n);
    } else {
	nq = *n;
	nw = max(1,*m);
    }
    if (! left && ! lsame_(side, "R")) {
	*info = -1;
    } else if (! notran && ! lsame_(trans, "C")) {
	*info = -2;
    } else if (*m < 0) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*k < 0 || *k > nq) {
	*info = -5;
    } else if (*lda < max(1,*k)) {
	*info = -7;
    } else if (*ldc < max(1,*m)) {
	*info = -10;
    }

    if (*info == 0) {
	if (*m == 0 || *n == 0) {
	    lwkopt = 1;
	} else {

/*           Determine the block size.  NB may be at most NBMAX, where */
/*           NBMAX is used to define the local array T. */

/* Computing MIN */
/* Writing concatenation */
	    i__3[0] = 1, a__1[0] = side;
	    i__3[1] = 1, a__1[1] = trans;
	    s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2);
	    i__1 = 64, i__2 = ilaenv_(&c__1, "ZUNMRQ", ch__1, m, n, k, &c_n1);
	    nb = min(i__1,i__2);
	    lwkopt = nw * nb;
	}
	work[1].r = (doublereal) lwkopt, work[1].i = 0.;

	if (*lwork < nw && ! lquery) {
	    *info = -12;
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("ZUNMRQ", &i__1);
	return 0;
    } else if (lquery) {
	return 0;
    }

/*     Quick return if possible */

    if (*m == 0 || *n == 0) {
	return 0;
    }

    nbmin = 2;
    ldwork = nw;
    if (nb > 1 && nb < *k) {
	iws = nw * nb;
	if (*lwork < iws) {
	    nb = *lwork / ldwork;
/* Computing MAX */
/* Writing concatenation */
	    i__3[0] = 1, a__1[0] = side;
	    i__3[1] = 1, a__1[1] = trans;
	    s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2);
	    i__1 = 2, i__2 = ilaenv_(&c__2, "ZUNMRQ", ch__1, m, n, k, &c_n1);
	    nbmin = max(i__1,i__2);
	}
    } else {
	iws = nw;
    }

    if (nb < nbmin || nb >= *k) {

/*        Use unblocked code */

	zunmr2_(side, trans, m, n, k, &a[a_offset], lda, &tau[1], &c__[
		c_offset], ldc, &work[1], &iinfo);
    } else {

/*        Use blocked code */

	if (left && ! notran || ! left && notran) {
	    i1 = 1;
	    i2 = *k;
	    i3 = nb;
	} else {
	    i1 = (*k - 1) / nb * nb + 1;
	    i2 = 1;
	    i3 = -nb;
	}

	if (left) {
	    ni = *n;
	} else {
	    mi = *m;
	}

	if (notran) {
	    *(unsigned char *)transt = 'C';
	} else {
	    *(unsigned char *)transt = 'N';
	}

	i__1 = i2;
	i__2 = i3;
	for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
/* Computing MIN */
	    i__4 = nb, i__5 = *k - i__ + 1;
	    ib = min(i__4,i__5);

/*           Form the triangular factor of the block reflector */
/*           H = H(i+ib-1) . . . H(i+1) H(i) */

	    i__4 = nq - *k + i__ + ib - 1;
	    zlarft_("Backward", "Rowwise", &i__4, &ib, &a[i__ + a_dim1], lda, 
		    &tau[i__], t, &c__65);
	    if (left) {

/*              H or H' is applied to C(1:m-k+i+ib-1,1:n) */

		mi = *m - *k + i__ + ib - 1;
	    } else {

/*              H or H' is applied to C(1:m,1:n-k+i+ib-1) */

		ni = *n - *k + i__ + ib - 1;
	    }

/*           Apply H or H' */

	    zlarfb_(side, transt, "Backward", "Rowwise", &mi, &ni, &ib, &a[
		    i__ + a_dim1], lda, t, &c__65, &c__[c_offset], ldc, &work[
		    1], &ldwork);
/* L10: */
	}
    }
    work[1].r = (doublereal) lwkopt, work[1].i = 0.;
    return 0;

/*     End of ZUNMRQ */

} /* zunmrq_ */