File:  [local] / rpl / lapack / lapack / zuncsd.f
Revision 1.4: download - view: text, annotated - select for diffs - revision graph
Mon Nov 21 20:43:23 2011 UTC (12 years, 5 months ago) by bertrand
Branches: MAIN
CVS tags: HEAD
Mise à jour de Lapack.

    1: *> \brief \b ZUNCSD
    2: *
    3: *  =========== DOCUMENTATION ===========
    4: *
    5: * Online html documentation available at 
    6: *            http://www.netlib.org/lapack/explore-html/ 
    7: *
    8: *> \htmlonly
    9: *> Download ZUNCSD + dependencies 
   10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zuncsd.f"> 
   11: *> [TGZ]</a> 
   12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zuncsd.f"> 
   13: *> [ZIP]</a> 
   14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zuncsd.f"> 
   15: *> [TXT]</a>
   16: *> \endhtmlonly 
   17: *
   18: *  Definition:
   19: *  ===========
   20: *
   21: *       RECURSIVE SUBROUTINE ZUNCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS,
   22: *                                    SIGNS, M, P, Q, X11, LDX11, X12,
   23: *                                    LDX12, X21, LDX21, X22, LDX22, THETA,
   24: *                                    U1, LDU1, U2, LDU2, V1T, LDV1T, V2T,
   25: *                                    LDV2T, WORK, LWORK, RWORK, LRWORK,
   26: *                                    IWORK, INFO )
   27:    28: *       .. Scalar Arguments ..
   29: *       CHARACTER          JOBU1, JOBU2, JOBV1T, JOBV2T, SIGNS, TRANS
   30: *       INTEGER            INFO, LDU1, LDU2, LDV1T, LDV2T, LDX11, LDX12,
   31: *      $                   LDX21, LDX22, LRWORK, LWORK, M, P, Q
   32: *       ..
   33: *       .. Array Arguments ..
   34: *       INTEGER            IWORK( * )
   35: *       DOUBLE PRECISION   THETA( * )
   36: *       DOUBLE PRECISION   RWORK( * )
   37: *       COMPLEX*16         U1( LDU1, * ), U2( LDU2, * ), V1T( LDV1T, * ),
   38: *      $                   V2T( LDV2T, * ), WORK( * ), X11( LDX11, * ),
   39: *      $                   X12( LDX12, * ), X21( LDX21, * ), X22( LDX22,
   40: *      $                   * )
   41: *       ..
   42: *  
   43: *
   44: *> \par Purpose:
   45: *  =============
   46: *>
   47: *> \verbatim
   48: *>
   49: *> ZUNCSD computes the CS decomposition of an M-by-M partitioned
   50: *> unitary matrix X:
   51: *>
   52: *>                                 [  I  0  0 |  0  0  0 ]
   53: *>                                 [  0  C  0 |  0 -S  0 ]
   54: *>     [ X11 | X12 ]   [ U1 |    ] [  0  0  0 |  0  0 -I ] [ V1 |    ]**H
   55: *> X = [-----------] = [---------] [---------------------] [---------]   .
   56: *>     [ X21 | X22 ]   [    | U2 ] [  0  0  0 |  I  0  0 ] [    | V2 ]
   57: *>                                 [  0  S  0 |  0  C  0 ]
   58: *>                                 [  0  0  I |  0  0  0 ]
   59: *>
   60: *> X11 is P-by-Q. The unitary matrices U1, U2, V1, and V2 are P-by-P,
   61: *> (M-P)-by-(M-P), Q-by-Q, and (M-Q)-by-(M-Q), respectively. C and S are
   62: *> R-by-R nonnegative diagonal matrices satisfying C^2 + S^2 = I, in
   63: *> which R = MIN(P,M-P,Q,M-Q).
   64: *> \endverbatim
   65: *
   66: *  Arguments:
   67: *  ==========
   68: *
   69: *> \param[in] JOBU1
   70: *> \verbatim
   71: *>          JOBU1 is CHARACTER
   72: *>          = 'Y':      U1 is computed;
   73: *>          otherwise:  U1 is not computed.
   74: *> \endverbatim
   75: *>
   76: *> \param[in] JOBU2
   77: *> \verbatim
   78: *>          JOBU2 is CHARACTER
   79: *>          = 'Y':      U2 is computed;
   80: *>          otherwise:  U2 is not computed.
   81: *> \endverbatim
   82: *>
   83: *> \param[in] JOBV1T
   84: *> \verbatim
   85: *>          JOBV1T is CHARACTER
   86: *>          = 'Y':      V1T is computed;
   87: *>          otherwise:  V1T is not computed.
   88: *> \endverbatim
   89: *>
   90: *> \param[in] JOBV2T
   91: *> \verbatim
   92: *>          JOBV2T is CHARACTER
   93: *>          = 'Y':      V2T is computed;
   94: *>          otherwise:  V2T is not computed.
   95: *> \endverbatim
   96: *>
   97: *> \param[in] TRANS
   98: *> \verbatim
   99: *>          TRANS is CHARACTER
  100: *>          = 'T':      X, U1, U2, V1T, and V2T are stored in row-major
  101: *>                      order;
  102: *>          otherwise:  X, U1, U2, V1T, and V2T are stored in column-
  103: *>                      major order.
  104: *> \endverbatim
  105: *>
  106: *> \param[in] SIGNS
  107: *> \verbatim
  108: *>          SIGNS is CHARACTER
  109: *>          = 'O':      The lower-left block is made nonpositive (the
  110: *>                      "other" convention);
  111: *>          otherwise:  The upper-right block is made nonpositive (the
  112: *>                      "default" convention).
  113: *> \endverbatim
  114: *>
  115: *> \param[in] M
  116: *> \verbatim
  117: *>          M is INTEGER
  118: *>          The number of rows and columns in X.
  119: *> \endverbatim
  120: *>
  121: *> \param[in] P
  122: *> \verbatim
  123: *>          P is INTEGER
  124: *>          The number of rows in X11 and X12. 0 <= P <= M.
  125: *> \endverbatim
  126: *>
  127: *> \param[in] Q
  128: *> \verbatim
  129: *>          Q is INTEGER
  130: *>          The number of columns in X11 and X21. 0 <= Q <= M.
  131: *> \endverbatim
  132: *>
  133: *> \param[in,out] X11
  134: *> \verbatim
  135: *>          X11 is COMPLEX*16 array, dimension (LDX11,Q)
  136: *>          On entry, part of the unitary matrix whose CSD is desired.
  137: *> \endverbatim
  138: *>
  139: *> \param[in] LDX11
  140: *> \verbatim
  141: *>          LDX11 is INTEGER
  142: *>          The leading dimension of X11. LDX11 >= MAX(1,P).
  143: *> \endverbatim
  144: *>
  145: *> \param[in,out] X12
  146: *> \verbatim
  147: *>          X12 is COMPLEX*16 array, dimension (LDX12,M-Q)
  148: *>          On entry, part of the unitary matrix whose CSD is desired.
  149: *> \endverbatim
  150: *>
  151: *> \param[in] LDX12
  152: *> \verbatim
  153: *>          LDX12 is INTEGER
  154: *>          The leading dimension of X12. LDX12 >= MAX(1,P).
  155: *> \endverbatim
  156: *>
  157: *> \param[in,out] X21
  158: *> \verbatim
  159: *>          X21 is COMPLEX*16 array, dimension (LDX21,Q)
  160: *>          On entry, part of the unitary matrix whose CSD is desired.
  161: *> \endverbatim
  162: *>
  163: *> \param[in] LDX21
  164: *> \verbatim
  165: *>          LDX21 is INTEGER
  166: *>          The leading dimension of X11. LDX21 >= MAX(1,M-P).
  167: *> \endverbatim
  168: *>
  169: *> \param[in,out] X22
  170: *> \verbatim
  171: *>          X22 is COMPLEX*16 array, dimension (LDX22,M-Q)
  172: *>          On entry, part of the unitary matrix whose CSD is desired.
  173: *> \endverbatim
  174: *>
  175: *> \param[in] LDX22
  176: *> \verbatim
  177: *>          LDX22 is INTEGER
  178: *>          The leading dimension of X11. LDX22 >= MAX(1,M-P).
  179: *> \endverbatim
  180: *>
  181: *> \param[out] THETA
  182: *> \verbatim
  183: *>          THETA is DOUBLE PRECISION array, dimension (R), in which R =
  184: *>          MIN(P,M-P,Q,M-Q).
  185: *>          C = DIAG( COS(THETA(1)), ... , COS(THETA(R)) ) and
  186: *>          S = DIAG( SIN(THETA(1)), ... , SIN(THETA(R)) ).
  187: *> \endverbatim
  188: *>
  189: *> \param[out] U1
  190: *> \verbatim
  191: *>          U1 is COMPLEX*16 array, dimension (P)
  192: *>          If JOBU1 = 'Y', U1 contains the P-by-P unitary matrix U1.
  193: *> \endverbatim
  194: *>
  195: *> \param[in] LDU1
  196: *> \verbatim
  197: *>          LDU1 is INTEGER
  198: *>          The leading dimension of U1. If JOBU1 = 'Y', LDU1 >=
  199: *>          MAX(1,P).
  200: *> \endverbatim
  201: *>
  202: *> \param[out] U2
  203: *> \verbatim
  204: *>          U2 is COMPLEX*16 array, dimension (M-P)
  205: *>          If JOBU2 = 'Y', U2 contains the (M-P)-by-(M-P) unitary
  206: *>          matrix U2.
  207: *> \endverbatim
  208: *>
  209: *> \param[in] LDU2
  210: *> \verbatim
  211: *>          LDU2 is INTEGER
  212: *>          The leading dimension of U2. If JOBU2 = 'Y', LDU2 >=
  213: *>          MAX(1,M-P).
  214: *> \endverbatim
  215: *>
  216: *> \param[out] V1T
  217: *> \verbatim
  218: *>          V1T is COMPLEX*16 array, dimension (Q)
  219: *>          If JOBV1T = 'Y', V1T contains the Q-by-Q matrix unitary
  220: *>          matrix V1**H.
  221: *> \endverbatim
  222: *>
  223: *> \param[in] LDV1T
  224: *> \verbatim
  225: *>          LDV1T is INTEGER
  226: *>          The leading dimension of V1T. If JOBV1T = 'Y', LDV1T >=
  227: *>          MAX(1,Q).
  228: *> \endverbatim
  229: *>
  230: *> \param[out] V2T
  231: *> \verbatim
  232: *>          V2T is COMPLEX*16 array, dimension (M-Q)
  233: *>          If JOBV2T = 'Y', V2T contains the (M-Q)-by-(M-Q) unitary
  234: *>          matrix V2**H.
  235: *> \endverbatim
  236: *>
  237: *> \param[in] LDV2T
  238: *> \verbatim
  239: *>          LDV2T is INTEGER
  240: *>          The leading dimension of V2T. If JOBV2T = 'Y', LDV2T >=
  241: *>          MAX(1,M-Q).
  242: *> \endverbatim
  243: *>
  244: *> \param[out] WORK
  245: *> \verbatim
  246: *>          WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
  247: *>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
  248: *> \endverbatim
  249: *>
  250: *> \param[in] LWORK
  251: *> \verbatim
  252: *>          LWORK is INTEGER
  253: *>          The dimension of the array WORK.
  254: *>
  255: *>          If LWORK = -1, then a workspace query is assumed; the routine
  256: *>          only calculates the optimal size of the WORK array, returns
  257: *>          this value as the first entry of the work array, and no error
  258: *>          message related to LWORK is issued by XERBLA.
  259: *> \endverbatim
  260: *>
  261: *> \param[out] RWORK
  262: *> \verbatim
  263: *>          RWORK is DOUBLE PRECISION array, dimension MAX(1,LRWORK)
  264: *>          On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK.
  265: *>          If INFO > 0 on exit, RWORK(2:R) contains the values PHI(1),
  266: *>          ..., PHI(R-1) that, together with THETA(1), ..., THETA(R),
  267: *>          define the matrix in intermediate bidiagonal-block form
  268: *>          remaining after nonconvergence. INFO specifies the number
  269: *>          of nonzero PHI's.
  270: *> \endverbatim
  271: *>
  272: *> \param[in] LRWORK
  273: *> \verbatim
  274: *>          LRWORK is INTEGER
  275: *>          The dimension of the array RWORK.
  276: *>
  277: *>          If LRWORK = -1, then a workspace query is assumed; the routine
  278: *>          only calculates the optimal size of the RWORK array, returns
  279: *>          this value as the first entry of the work array, and no error
  280: *>          message related to LRWORK is issued by XERBLA.
  281: *> \endverbatim
  282: *>
  283: *> \param[out] IWORK
  284: *> \verbatim
  285: *>          IWORK is INTEGER array, dimension (M-MIN(P,M-P,Q,M-Q))
  286: *> \endverbatim
  287: *>
  288: *> \param[out] INFO
  289: *> \verbatim
  290: *>          INFO is INTEGER
  291: *>          = 0:  successful exit.
  292: *>          < 0:  if INFO = -i, the i-th argument had an illegal value.
  293: *>          > 0:  ZBBCSD did not converge. See the description of RWORK
  294: *>                above for details.
  295: *> \endverbatim
  296: *
  297: *> \par References:
  298: *  ================
  299: *>
  300: *>  [1] Brian D. Sutton. Computing the complete CS decomposition. Numer.
  301: *>      Algorithms, 50(1):33-65, 2009.
  302: *
  303: *  Authors:
  304: *  ========
  305: *
  306: *> \author Univ. of Tennessee 
  307: *> \author Univ. of California Berkeley 
  308: *> \author Univ. of Colorado Denver 
  309: *> \author NAG Ltd. 
  310: *
  311: *> \date November 2011
  312: *
  313: *> \ingroup complex16OTHERcomputational
  314: *
  315: *  =====================================================================
  316:       RECURSIVE SUBROUTINE ZUNCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS,
  317:      $                             SIGNS, M, P, Q, X11, LDX11, X12,
  318:      $                             LDX12, X21, LDX21, X22, LDX22, THETA,
  319:      $                             U1, LDU1, U2, LDU2, V1T, LDV1T, V2T,
  320:      $                             LDV2T, WORK, LWORK, RWORK, LRWORK,
  321:      $                             IWORK, INFO )
  322: *
  323: *  -- LAPACK computational routine (version 3.4.0) --
  324: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
  325: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
  326: *     November 2011
  327: *
  328: *     .. Scalar Arguments ..
  329:       CHARACTER          JOBU1, JOBU2, JOBV1T, JOBV2T, SIGNS, TRANS
  330:       INTEGER            INFO, LDU1, LDU2, LDV1T, LDV2T, LDX11, LDX12,
  331:      $                   LDX21, LDX22, LRWORK, LWORK, M, P, Q
  332: *     ..
  333: *     .. Array Arguments ..
  334:       INTEGER            IWORK( * )
  335:       DOUBLE PRECISION   THETA( * )
  336:       DOUBLE PRECISION   RWORK( * )
  337:       COMPLEX*16         U1( LDU1, * ), U2( LDU2, * ), V1T( LDV1T, * ),
  338:      $                   V2T( LDV2T, * ), WORK( * ), X11( LDX11, * ),
  339:      $                   X12( LDX12, * ), X21( LDX21, * ), X22( LDX22,
  340:      $                   * )
  341: *     ..
  342: *
  343: *  ===================================================================
  344: *
  345: *     .. Parameters ..
  346:       DOUBLE PRECISION   REALONE
  347:       PARAMETER          ( REALONE = 1.0D0 )
  348:       COMPLEX*16         NEGONE, ONE, PIOVER2, ZERO
  349:       PARAMETER          ( NEGONE = (-1.0D0,0.0D0), ONE = (1.0D0,0.0D0),
  350:      $                     PIOVER2 = 1.57079632679489662D0,
  351:      $                     ZERO = (0.0D0,0.0D0) )
  352: *     ..
  353: *     .. Local Scalars ..
  354:       CHARACTER          TRANST, SIGNST
  355:       INTEGER            CHILDINFO, I, IB11D, IB11E, IB12D, IB12E,
  356:      $                   IB21D, IB21E, IB22D, IB22E, IBBCSD, IORBDB,
  357:      $                   IORGLQ, IORGQR, IPHI, ITAUP1, ITAUP2, ITAUQ1,
  358:      $                   ITAUQ2, J, LBBCSDWORK, LBBCSDWORKMIN,
  359:      $                   LBBCSDWORKOPT, LORBDBWORK, LORBDBWORKMIN,
  360:      $                   LORBDBWORKOPT, LORGLQWORK, LORGLQWORKMIN,
  361:      $                   LORGLQWORKOPT, LORGQRWORK, LORGQRWORKMIN,
  362:      $                   LORGQRWORKOPT, LWORKMIN, LWORKOPT
  363:       LOGICAL            COLMAJOR, DEFAULTSIGNS, LQUERY, WANTU1, WANTU2,
  364:      $                   WANTV1T, WANTV2T
  365:       INTEGER            LRWORKMIN, LRWORKOPT
  366:       LOGICAL            LRQUERY
  367: *     ..
  368: *     .. External Subroutines ..
  369:       EXTERNAL           XERBLA, ZBBCSD, ZLACPY, ZLAPMR, ZLAPMT, ZLASCL,
  370:      $                   ZLASET, ZUNBDB, ZUNGLQ, ZUNGQR
  371: *     ..
  372: *     .. External Functions ..
  373:       LOGICAL            LSAME
  374:       EXTERNAL           LSAME
  375: *     ..
  376: *     .. Intrinsic Functions
  377:       INTRINSIC          COS, INT, MAX, MIN, SIN
  378: *     ..
  379: *     .. Executable Statements ..
  380: *
  381: *     Test input arguments
  382: *
  383:       INFO = 0
  384:       WANTU1 = LSAME( JOBU1, 'Y' )
  385:       WANTU2 = LSAME( JOBU2, 'Y' )
  386:       WANTV1T = LSAME( JOBV1T, 'Y' )
  387:       WANTV2T = LSAME( JOBV2T, 'Y' )
  388:       COLMAJOR = .NOT. LSAME( TRANS, 'T' )
  389:       DEFAULTSIGNS = .NOT. LSAME( SIGNS, 'O' )
  390:       LQUERY = LWORK .EQ. -1
  391:       LRQUERY = LRWORK .EQ. -1
  392:       IF( M .LT. 0 ) THEN
  393:          INFO = -7
  394:       ELSE IF( P .LT. 0 .OR. P .GT. M ) THEN
  395:          INFO = -8
  396:       ELSE IF( Q .LT. 0 .OR. Q .GT. M ) THEN
  397:          INFO = -9
  398:       ELSE IF( ( COLMAJOR .AND. LDX11 .LT. MAX(1,P) ) .OR.
  399:      $         ( .NOT.COLMAJOR .AND. LDX11 .LT. MAX(1,Q) ) ) THEN
  400:          INFO = -11
  401:       ELSE IF( WANTU1 .AND. LDU1 .LT. P ) THEN
  402:          INFO = -20
  403:       ELSE IF( WANTU2 .AND. LDU2 .LT. M-P ) THEN
  404:          INFO = -22
  405:       ELSE IF( WANTV1T .AND. LDV1T .LT. Q ) THEN
  406:          INFO = -24
  407:       ELSE IF( WANTV2T .AND. LDV2T .LT. M-Q ) THEN
  408:          INFO = -26
  409:       END IF
  410: *
  411: *     Work with transpose if convenient
  412: *
  413:       IF( INFO .EQ. 0 .AND. MIN( P, M-P ) .LT. MIN( Q, M-Q ) ) THEN
  414:          IF( COLMAJOR ) THEN
  415:             TRANST = 'T'
  416:          ELSE
  417:             TRANST = 'N'
  418:          END IF
  419:          IF( DEFAULTSIGNS ) THEN
  420:             SIGNST = 'O'
  421:          ELSE
  422:             SIGNST = 'D'
  423:          END IF
  424:          CALL ZUNCSD( JOBV1T, JOBV2T, JOBU1, JOBU2, TRANST, SIGNST, M,
  425:      $                Q, P, X11, LDX11, X21, LDX21, X12, LDX12, X22,
  426:      $                LDX22, THETA, V1T, LDV1T, V2T, LDV2T, U1, LDU1,
  427:      $                U2, LDU2, WORK, LWORK, RWORK, LRWORK, IWORK,
  428:      $                INFO )
  429:          RETURN
  430:       END IF
  431: *
  432: *     Work with permutation [ 0 I; I 0 ] * X * [ 0 I; I 0 ] if
  433: *     convenient
  434: *
  435:       IF( INFO .EQ. 0 .AND. M-Q .LT. Q ) THEN
  436:          IF( DEFAULTSIGNS ) THEN
  437:             SIGNST = 'O'
  438:          ELSE
  439:             SIGNST = 'D'
  440:          END IF
  441:          CALL ZUNCSD( JOBU2, JOBU1, JOBV2T, JOBV1T, TRANS, SIGNST, M,
  442:      $                M-P, M-Q, X22, LDX22, X21, LDX21, X12, LDX12, X11,
  443:      $                LDX11, THETA, U2, LDU2, U1, LDU1, V2T, LDV2T, V1T,
  444:      $                LDV1T, WORK, LWORK, RWORK, LRWORK, IWORK, INFO )
  445:          RETURN
  446:       END IF
  447: *
  448: *     Compute workspace
  449: *
  450:       IF( INFO .EQ. 0 ) THEN
  451: *
  452: *        Real workspace
  453: *
  454:          IPHI = 2
  455:          IB11D = IPHI + MAX( 1, Q - 1 )
  456:          IB11E = IB11D + MAX( 1, Q )
  457:          IB12D = IB11E + MAX( 1, Q - 1 )
  458:          IB12E = IB12D + MAX( 1, Q )
  459:          IB21D = IB12E + MAX( 1, Q - 1 )
  460:          IB21E = IB21D + MAX( 1, Q )
  461:          IB22D = IB21E + MAX( 1, Q - 1 )
  462:          IB22E = IB22D + MAX( 1, Q )
  463:          IBBCSD = IB22E + MAX( 1, Q - 1 )
  464:          CALL ZBBCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS, M, P, Q, 0,
  465:      $                0, U1, LDU1, U2, LDU2, V1T, LDV1T, V2T, LDV2T, 0,
  466:      $                0, 0, 0, 0, 0, 0, 0, RWORK, -1, CHILDINFO )
  467:          LBBCSDWORKOPT = INT( RWORK(1) )
  468:          LBBCSDWORKMIN = LBBCSDWORKOPT
  469:          LRWORKOPT = IBBCSD + LBBCSDWORKOPT - 1
  470:          LRWORKMIN = IBBCSD + LBBCSDWORKMIN - 1
  471:          RWORK(1) = LRWORKOPT
  472: *
  473: *        Complex workspace
  474: *
  475:          ITAUP1 = 2
  476:          ITAUP2 = ITAUP1 + MAX( 1, P )
  477:          ITAUQ1 = ITAUP2 + MAX( 1, M - P )
  478:          ITAUQ2 = ITAUQ1 + MAX( 1, Q )
  479:          IORGQR = ITAUQ2 + MAX( 1, M - Q )
  480:          CALL ZUNGQR( M-Q, M-Q, M-Q, 0, MAX(1,M-Q), 0, WORK, -1,
  481:      $                CHILDINFO )
  482:          LORGQRWORKOPT = INT( WORK(1) )
  483:          LORGQRWORKMIN = MAX( 1, M - Q )
  484:          IORGLQ = ITAUQ2 + MAX( 1, M - Q )
  485:          CALL ZUNGLQ( M-Q, M-Q, M-Q, 0, MAX(1,M-Q), 0, WORK, -1,
  486:      $                CHILDINFO )
  487:          LORGLQWORKOPT = INT( WORK(1) )
  488:          LORGLQWORKMIN = MAX( 1, M - Q )
  489:          IORBDB = ITAUQ2 + MAX( 1, M - Q )
  490:          CALL ZUNBDB( TRANS, SIGNS, M, P, Q, X11, LDX11, X12, LDX12,
  491:      $                X21, LDX21, X22, LDX22, 0, 0, 0, 0, 0, 0, WORK,
  492:      $                -1, CHILDINFO )
  493:          LORBDBWORKOPT = INT( WORK(1) )
  494:          LORBDBWORKMIN = LORBDBWORKOPT
  495:          LWORKOPT = MAX( IORGQR + LORGQRWORKOPT, IORGLQ + LORGLQWORKOPT,
  496:      $              IORBDB + LORBDBWORKOPT ) - 1
  497:          LWORKMIN = MAX( IORGQR + LORGQRWORKMIN, IORGLQ + LORGLQWORKMIN,
  498:      $              IORBDB + LORBDBWORKMIN ) - 1
  499:          WORK(1) = MAX(LWORKOPT,LWORKMIN)
  500: *
  501:          IF( LWORK .LT. LWORKMIN
  502:      $       .AND. .NOT. ( LQUERY .OR. LRQUERY ) ) THEN
  503:             INFO = -22
  504:          ELSE IF( LRWORK .LT. LRWORKMIN
  505:      $            .AND. .NOT. ( LQUERY .OR. LRQUERY ) ) THEN
  506:             INFO = -24
  507:          ELSE
  508:             LORGQRWORK = LWORK - IORGQR + 1
  509:             LORGLQWORK = LWORK - IORGLQ + 1
  510:             LORBDBWORK = LWORK - IORBDB + 1
  511:             LBBCSDWORK = LRWORK - IBBCSD + 1
  512:          END IF
  513:       END IF
  514: *
  515: *     Abort if any illegal arguments
  516: *
  517:       IF( INFO .NE. 0 ) THEN
  518:          CALL XERBLA( 'ZUNCSD', -INFO )
  519:          RETURN
  520:       ELSE IF( LQUERY .OR. LRQUERY ) THEN
  521:          RETURN
  522:       END IF
  523: *
  524: *     Transform to bidiagonal block form
  525: *
  526:       CALL ZUNBDB( TRANS, SIGNS, M, P, Q, X11, LDX11, X12, LDX12, X21,
  527:      $             LDX21, X22, LDX22, THETA, RWORK(IPHI), WORK(ITAUP1),
  528:      $             WORK(ITAUP2), WORK(ITAUQ1), WORK(ITAUQ2),
  529:      $             WORK(IORBDB), LORBDBWORK, CHILDINFO )
  530: *
  531: *     Accumulate Householder reflectors
  532: *
  533:       IF( COLMAJOR ) THEN
  534:          IF( WANTU1 .AND. P .GT. 0 ) THEN
  535:             CALL ZLACPY( 'L', P, Q, X11, LDX11, U1, LDU1 )
  536:             CALL ZUNGQR( P, P, Q, U1, LDU1, WORK(ITAUP1), WORK(IORGQR),
  537:      $                   LORGQRWORK, INFO)
  538:          END IF
  539:          IF( WANTU2 .AND. M-P .GT. 0 ) THEN
  540:             CALL ZLACPY( 'L', M-P, Q, X21, LDX21, U2, LDU2 )
  541:             CALL ZUNGQR( M-P, M-P, Q, U2, LDU2, WORK(ITAUP2),
  542:      $                   WORK(IORGQR), LORGQRWORK, INFO )
  543:          END IF
  544:          IF( WANTV1T .AND. Q .GT. 0 ) THEN
  545:             CALL ZLACPY( 'U', Q-1, Q-1, X11(1,2), LDX11, V1T(2,2),
  546:      $                   LDV1T )
  547:             V1T(1, 1) = ONE
  548:             DO J = 2, Q
  549:                V1T(1,J) = ZERO
  550:                V1T(J,1) = ZERO
  551:             END DO
  552:             CALL ZUNGLQ( Q-1, Q-1, Q-1, V1T(2,2), LDV1T, WORK(ITAUQ1),
  553:      $                   WORK(IORGLQ), LORGLQWORK, INFO )
  554:          END IF
  555:          IF( WANTV2T .AND. M-Q .GT. 0 ) THEN
  556:             CALL ZLACPY( 'U', P, M-Q, X12, LDX12, V2T, LDV2T )
  557:             CALL ZLACPY( 'U', M-P-Q, M-P-Q, X22(Q+1,P+1), LDX22,
  558:      $                   V2T(P+1,P+1), LDV2T )
  559:             CALL ZUNGLQ( M-Q, M-Q, M-Q, V2T, LDV2T, WORK(ITAUQ2),
  560:      $                   WORK(IORGLQ), LORGLQWORK, INFO )
  561:          END IF
  562:       ELSE
  563:          IF( WANTU1 .AND. P .GT. 0 ) THEN
  564:             CALL ZLACPY( 'U', Q, P, X11, LDX11, U1, LDU1 )
  565:             CALL ZUNGLQ( P, P, Q, U1, LDU1, WORK(ITAUP1), WORK(IORGLQ),
  566:      $                   LORGLQWORK, INFO)
  567:          END IF
  568:          IF( WANTU2 .AND. M-P .GT. 0 ) THEN
  569:             CALL ZLACPY( 'U', Q, M-P, X21, LDX21, U2, LDU2 )
  570:             CALL ZUNGLQ( M-P, M-P, Q, U2, LDU2, WORK(ITAUP2),
  571:      $                   WORK(IORGLQ), LORGLQWORK, INFO )
  572:          END IF
  573:          IF( WANTV1T .AND. Q .GT. 0 ) THEN
  574:             CALL ZLACPY( 'L', Q-1, Q-1, X11(2,1), LDX11, V1T(2,2),
  575:      $                   LDV1T )
  576:             V1T(1, 1) = ONE
  577:             DO J = 2, Q
  578:                V1T(1,J) = ZERO
  579:                V1T(J,1) = ZERO
  580:             END DO
  581:             CALL ZUNGQR( Q-1, Q-1, Q-1, V1T(2,2), LDV1T, WORK(ITAUQ1),
  582:      $                   WORK(IORGQR), LORGQRWORK, INFO )
  583:          END IF
  584:          IF( WANTV2T .AND. M-Q .GT. 0 ) THEN
  585:             CALL ZLACPY( 'L', M-Q, P, X12, LDX12, V2T, LDV2T )
  586:             CALL ZLACPY( 'L', M-P-Q, M-P-Q, X22(P+1,Q+1), LDX22,
  587:      $                   V2T(P+1,P+1), LDV2T )
  588:             CALL ZUNGQR( M-Q, M-Q, M-Q, V2T, LDV2T, WORK(ITAUQ2),
  589:      $                   WORK(IORGQR), LORGQRWORK, INFO )
  590:          END IF
  591:       END IF
  592: *
  593: *     Compute the CSD of the matrix in bidiagonal-block form
  594: *
  595:       CALL ZBBCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS, M, P, Q, THETA,
  596:      $             RWORK(IPHI), U1, LDU1, U2, LDU2, V1T, LDV1T, V2T,
  597:      $             LDV2T, RWORK(IB11D), RWORK(IB11E), RWORK(IB12D),
  598:      $             RWORK(IB12E), RWORK(IB21D), RWORK(IB21E),
  599:      $             RWORK(IB22D), RWORK(IB22E), RWORK(IBBCSD),
  600:      $             LBBCSDWORK, INFO )
  601: *
  602: *     Permute rows and columns to place identity submatrices in top-
  603: *     left corner of (1,1)-block and/or bottom-right corner of (1,2)-
  604: *     block and/or bottom-right corner of (2,1)-block and/or top-left
  605: *     corner of (2,2)-block 
  606: *
  607:       IF( Q .GT. 0 .AND. WANTU2 ) THEN
  608:          DO I = 1, Q
  609:             IWORK(I) = M - P - Q + I
  610:          END DO
  611:          DO I = Q + 1, M - P
  612:             IWORK(I) = I - Q
  613:          END DO
  614:          IF( COLMAJOR ) THEN
  615:             CALL ZLAPMT( .FALSE., M-P, M-P, U2, LDU2, IWORK )
  616:          ELSE
  617:             CALL ZLAPMR( .FALSE., M-P, M-P, U2, LDU2, IWORK )
  618:          END IF
  619:       END IF
  620:       IF( M .GT. 0 .AND. WANTV2T ) THEN
  621:          DO I = 1, P
  622:             IWORK(I) = M - P - Q + I
  623:          END DO
  624:          DO I = P + 1, M - Q
  625:             IWORK(I) = I - P
  626:          END DO
  627:          IF( .NOT. COLMAJOR ) THEN
  628:             CALL ZLAPMT( .FALSE., M-Q, M-Q, V2T, LDV2T, IWORK )
  629:          ELSE
  630:             CALL ZLAPMR( .FALSE., M-Q, M-Q, V2T, LDV2T, IWORK )
  631:          END IF
  632:       END IF
  633: *
  634:       RETURN
  635: *
  636: *     End ZUNCSD
  637: *
  638:       END
  639: 

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