741 lines
		
	
	
		
			26 KiB
		
	
	
	
		
			Fortran
		
	
	
	
			
		
		
	
	
			741 lines
		
	
	
		
			26 KiB
		
	
	
	
		
			Fortran
		
	
	
	
| *> \brief \b SORCSD2BY1
 | |
| *
 | |
| *  =========== DOCUMENTATION ===========
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| *
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| * Online html documentation available at
 | |
| *            http://www.netlib.org/lapack/explore-html/
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| *
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| *> \htmlonly
 | |
| *> Download SORCSD2BY1 + dependencies
 | |
| *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/sorcsd2by1.f">
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| *> [TGZ]</a>
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| *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/sorcsd2by1.f">
 | |
| *> [ZIP]</a>
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| *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/sorcsd2by1.f">
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| *> [TXT]</a>
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| *> \endhtmlonly
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| *
 | |
| *  Definition:
 | |
| *  ===========
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| *
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| *       SUBROUTINE SORCSD2BY1( JOBU1, JOBU2, JOBV1T, M, P, Q, X11, LDX11,
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| *                              X21, LDX21, THETA, U1, LDU1, U2, LDU2, V1T,
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| *                              LDV1T, WORK, LWORK, IWORK, INFO )
 | |
| *
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| *       .. Scalar Arguments ..
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| *       CHARACTER          JOBU1, JOBU2, JOBV1T
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| *       INTEGER            INFO, LDU1, LDU2, LDV1T, LWORK, LDX11, LDX21,
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| *      $                   M, P, Q
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| *       ..
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| *       .. Array Arguments ..
 | |
| *       REAL               THETA(*)
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| *       REAL               U1(LDU1,*), U2(LDU2,*), V1T(LDV1T,*), WORK(*),
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| *      $                   X11(LDX11,*), X21(LDX21,*)
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| *       INTEGER            IWORK(*)
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| *       ..
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| *
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| *
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| *> \par Purpose:
 | |
| *  =============
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| *>
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| *>\verbatim
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| *>
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| *> SORCSD2BY1 computes the CS decomposition of an M-by-Q matrix X with
 | |
| *> orthonormal columns that has been partitioned into a 2-by-1 block
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| *> structure:
 | |
| *>
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| *>                                [  I1 0  0 ]
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| *>                                [  0  C  0 ]
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| *>          [ X11 ]   [ U1 |    ] [  0  0  0 ]
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| *>      X = [-----] = [---------] [----------] V1**T .
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| *>          [ X21 ]   [    | U2 ] [  0  0  0 ]
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| *>                                [  0  S  0 ]
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| *>                                [  0  0  I2]
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| *>
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| *> X11 is P-by-Q. The orthogonal matrices U1, U2, and V1 are P-by-P,
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| *> (M-P)-by-(M-P), and Q-by-Q, respectively. C and S are R-by-R
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| *> nonnegative diagonal matrices satisfying C^2 + S^2 = I, in which
 | |
| *> R = MIN(P,M-P,Q,M-Q). I1 is a K1-by-K1 identity matrix and I2 is a
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| *> K2-by-K2 identity matrix, where K1 = MAX(Q+P-M,0), K2 = MAX(Q-P,0).
 | |
| *> \endverbatim
 | |
| *
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| *  Arguments:
 | |
| *  ==========
 | |
| *
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| *> \param[in] JOBU1
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| *> \verbatim
 | |
| *>          JOBU1 is CHARACTER
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| *>          = 'Y':      U1 is computed;
 | |
| *>          otherwise:  U1 is not computed.
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| *> \endverbatim
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| *>
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| *> \param[in] JOBU2
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| *> \verbatim
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| *>          JOBU2 is CHARACTER
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| *>          = 'Y':      U2 is computed;
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| *>          otherwise:  U2 is not computed.
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| *> \endverbatim
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| *>
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| *> \param[in] JOBV1T
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| *> \verbatim
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| *>          JOBV1T is CHARACTER
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| *>          = 'Y':      V1T is computed;
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| *>          otherwise:  V1T is not computed.
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| *> \endverbatim
 | |
| *>
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| *> \param[in] M
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| *> \verbatim
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| *>          M is INTEGER
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| *>          The number of rows in X.
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| *> \endverbatim
 | |
| *>
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| *> \param[in] P
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| *> \verbatim
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| *>          P is INTEGER
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| *>          The number of rows in X11. 0 <= P <= M.
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[in] Q
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| *> \verbatim
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| *>          Q is INTEGER
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| *>          The number of columns in X11 and X21. 0 <= Q <= M.
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[in,out] X11
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| *> \verbatim
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| *>          X11 is REAL array, dimension (LDX11,Q)
 | |
| *>          On entry, part of the orthogonal matrix whose CSD is desired.
 | |
| *> \endverbatim
 | |
| *>
 | |
| *> \param[in] LDX11
 | |
| *> \verbatim
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| *>          LDX11 is INTEGER
 | |
| *>          The leading dimension of X11. LDX11 >= MAX(1,P).
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[in,out] X21
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| *> \verbatim
 | |
| *>          X21 is REAL array, dimension (LDX21,Q)
 | |
| *>          On entry, part of the orthogonal matrix whose CSD is desired.
 | |
| *> \endverbatim
 | |
| *>
 | |
| *> \param[in] LDX21
 | |
| *> \verbatim
 | |
| *>          LDX21 is INTEGER
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| *>           The leading dimension of X21. LDX21 >= MAX(1,M-P).
 | |
| *> \endverbatim
 | |
| *>
 | |
| *> \param[out] THETA
 | |
| *> \verbatim
 | |
| *>          THETA is REAL array, dimension (R), in which R =
 | |
| *>          MIN(P,M-P,Q,M-Q).
 | |
| *>          C = DIAG( COS(THETA(1)), ... , COS(THETA(R)) ) and
 | |
| *>          S = DIAG( SIN(THETA(1)), ... , SIN(THETA(R)) ).
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[out] U1
 | |
| *> \verbatim
 | |
| *>          U1 is REAL array, dimension (P)
 | |
| *>          If JOBU1 = 'Y', U1 contains the P-by-P orthogonal matrix U1.
 | |
| *> \endverbatim
 | |
| *>
 | |
| *> \param[in] LDU1
 | |
| *> \verbatim
 | |
| *>          LDU1 is INTEGER
 | |
| *>          The leading dimension of U1. If JOBU1 = 'Y', LDU1 >=
 | |
| *>          MAX(1,P).
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[out] U2
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| *> \verbatim
 | |
| *>          U2 is REAL array, dimension (M-P)
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| *>          If JOBU2 = 'Y', U2 contains the (M-P)-by-(M-P) orthogonal
 | |
| *>          matrix U2.
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[in] LDU2
 | |
| *> \verbatim
 | |
| *>          LDU2 is INTEGER
 | |
| *>          The leading dimension of U2. If JOBU2 = 'Y', LDU2 >=
 | |
| *>          MAX(1,M-P).
 | |
| *> \endverbatim
 | |
| *>
 | |
| *> \param[out] V1T
 | |
| *> \verbatim
 | |
| *>          V1T is REAL array, dimension (Q)
 | |
| *>          If JOBV1T = 'Y', V1T contains the Q-by-Q matrix orthogonal
 | |
| *>          matrix V1**T.
 | |
| *> \endverbatim
 | |
| *>
 | |
| *> \param[in] LDV1T
 | |
| *> \verbatim
 | |
| *>          LDV1T is INTEGER
 | |
| *>          The leading dimension of V1T. If JOBV1T = 'Y', LDV1T >=
 | |
| *>          MAX(1,Q).
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[out] WORK
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| *> \verbatim
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| *>          WORK is REAL array, dimension (MAX(1,LWORK))
 | |
| *>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
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| *>          If INFO > 0 on exit, WORK(2:R) contains the values PHI(1),
 | |
| *>          ..., PHI(R-1) that, together with THETA(1), ..., THETA(R),
 | |
| *>          define the matrix in intermediate bidiagonal-block form
 | |
| *>          remaining after nonconvergence. INFO specifies the number
 | |
| *>          of nonzero PHI's.
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[in] LWORK
 | |
| *> \verbatim
 | |
| *>          LWORK is INTEGER
 | |
| *>          The dimension of the array WORK.
 | |
| *>
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| *>          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.
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[out] IWORK
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| *> \verbatim
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| *>          IWORK is INTEGER array, dimension (M-MIN(P,M-P,Q,M-Q))
 | |
| *> \endverbatim
 | |
| *>
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| *> \param[out] INFO
 | |
| *> \verbatim
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| *>          INFO is INTEGER
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| *>          = 0:  successful exit.
 | |
| *>          < 0:  if INFO = -i, the i-th argument had an illegal value.
 | |
| *>          > 0:  SBBCSD did not converge. See the description of WORK
 | |
| *>                above for details.
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| *> \endverbatim
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| *
 | |
| *> \par References:
 | |
| *  ================
 | |
| *>
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| *>  [1] Brian D. Sutton. Computing the complete CS decomposition. Numer.
 | |
| *>      Algorithms, 50(1):33-65, 2009.
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| *
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| *  Authors:
 | |
| *  ========
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| *
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| *> \author Univ. of Tennessee
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| *> \author Univ. of California Berkeley
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| *> \author Univ. of Colorado Denver
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| *> \author NAG Ltd.
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| *
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| *> \date July 2012
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| *
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| *> \ingroup realOTHERcomputational
 | |
| *
 | |
| *  =====================================================================
 | |
|       SUBROUTINE SORCSD2BY1( JOBU1, JOBU2, JOBV1T, M, P, Q, X11, LDX11,
 | |
|      $                       X21, LDX21, THETA, U1, LDU1, U2, LDU2, V1T,
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|      $                       LDV1T, WORK, LWORK, IWORK, INFO )
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| *
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| *  -- LAPACK computational routine (version 3.7.1) --
 | |
| *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
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| *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
 | |
| *     July 2012
 | |
| *
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| *     .. Scalar Arguments ..
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|       CHARACTER          JOBU1, JOBU2, JOBV1T
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|       INTEGER            INFO, LDU1, LDU2, LDV1T, LWORK, LDX11, LDX21,
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|      $                   M, P, Q
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| *     ..
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| *     .. Array Arguments ..
 | |
|       REAL               THETA(*)
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|       REAL               U1(LDU1,*), U2(LDU2,*), V1T(LDV1T,*), WORK(*),
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|      $                   X11(LDX11,*), X21(LDX21,*)
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|       INTEGER            IWORK(*)
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| *     ..
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| *
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| *  =====================================================================
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| *
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| *     .. Parameters ..
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|       REAL               ONE, ZERO
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|       PARAMETER          ( ONE = 1.0E0, ZERO = 0.0E0 )
 | |
| *     ..
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| *     .. Local Scalars ..
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|       INTEGER            CHILDINFO, I, IB11D, IB11E, IB12D, IB12E,
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|      $                   IB21D, IB21E, IB22D, IB22E, IBBCSD, IORBDB,
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|      $                   IORGLQ, IORGQR, IPHI, ITAUP1, ITAUP2, ITAUQ1,
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|      $                   J, LBBCSD, LORBDB, LORGLQ, LORGLQMIN,
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|      $                   LORGLQOPT, LORGQR, LORGQRMIN, LORGQROPT,
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|      $                   LWORKMIN, LWORKOPT, R
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|       LOGICAL            LQUERY, WANTU1, WANTU2, WANTV1T
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| *     ..
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| *     .. Local Arrays ..
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|       REAL               DUM1(1), DUM2(1,1)
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| *     ..
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| *     .. External Subroutines ..
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|       EXTERNAL           SBBCSD, SCOPY, SLACPY, SLAPMR, SLAPMT, SORBDB1,
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|      $                   SORBDB2, SORBDB3, SORBDB4, SORGLQ, SORGQR,
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|      $                   XERBLA
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| *     ..
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| *     .. External Functions ..
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|       LOGICAL            LSAME
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|       EXTERNAL           LSAME
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| *     ..
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| *     .. Intrinsic Function ..
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|       INTRINSIC          INT, MAX, MIN
 | |
| *     ..
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| *     .. Executable Statements ..
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| *
 | |
| *     Test input arguments
 | |
| *
 | |
|       INFO = 0
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|       WANTU1 = LSAME( JOBU1, 'Y' )
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|       WANTU2 = LSAME( JOBU2, 'Y' )
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|       WANTV1T = LSAME( JOBV1T, 'Y' )
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|       LQUERY = LWORK .EQ. -1
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| *
 | |
|       IF( M .LT. 0 ) THEN
 | |
|          INFO = -4
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|       ELSE IF( P .LT. 0 .OR. P .GT. M ) THEN
 | |
|          INFO = -5
 | |
|       ELSE IF( Q .LT. 0 .OR. Q .GT. M ) THEN
 | |
|          INFO = -6
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|       ELSE IF( LDX11 .LT. MAX( 1, P ) ) THEN
 | |
|          INFO = -8
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|       ELSE IF( LDX21 .LT. MAX( 1, M-P ) ) THEN
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|          INFO = -10
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|       ELSE IF( WANTU1 .AND. LDU1 .LT. MAX( 1, P ) ) THEN
 | |
|          INFO = -13
 | |
|       ELSE IF( WANTU2 .AND. LDU2 .LT. MAX( 1, M - P ) ) THEN
 | |
|          INFO = -15
 | |
|       ELSE IF( WANTV1T .AND. LDV1T .LT. MAX( 1, Q ) ) THEN
 | |
|          INFO = -17
 | |
|       END IF
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| *
 | |
|       R = MIN( P, M-P, Q, M-Q )
 | |
| *
 | |
| *     Compute workspace
 | |
| *
 | |
| *       WORK layout:
 | |
| *     |-------------------------------------------------------|
 | |
| *     | LWORKOPT (1)                                          |
 | |
| *     |-------------------------------------------------------|
 | |
| *     | PHI (MAX(1,R-1))                                      |
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| *     |-------------------------------------------------------|
 | |
| *     | TAUP1 (MAX(1,P))                        | B11D (R)    |
 | |
| *     | TAUP2 (MAX(1,M-P))                      | B11E (R-1)  |
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| *     | TAUQ1 (MAX(1,Q))                        | B12D (R)    |
 | |
| *     |-----------------------------------------| B12E (R-1)  |
 | |
| *     | SORBDB WORK | SORGQR WORK | SORGLQ WORK | B21D (R)    |
 | |
| *     |             |             |             | B21E (R-1)  |
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| *     |             |             |             | B22D (R)    |
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| *     |             |             |             | B22E (R-1)  |
 | |
| *     |             |             |             | SBBCSD WORK |
 | |
| *     |-------------------------------------------------------|
 | |
| *
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|       IF( INFO .EQ. 0 ) THEN
 | |
|          IPHI = 2
 | |
|          IB11D = IPHI + MAX( 1, R-1 )
 | |
|          IB11E = IB11D + MAX( 1, R )
 | |
|          IB12D = IB11E + MAX( 1, R - 1 )
 | |
|          IB12E = IB12D + MAX( 1, R )
 | |
|          IB21D = IB12E + MAX( 1, R - 1 )
 | |
|          IB21E = IB21D + MAX( 1, R )
 | |
|          IB22D = IB21E + MAX( 1, R - 1 )
 | |
|          IB22E = IB22D + MAX( 1, R )
 | |
|          IBBCSD = IB22E + MAX( 1, R - 1 )
 | |
|          ITAUP1 = IPHI + MAX( 1, R-1 )
 | |
|          ITAUP2 = ITAUP1 + MAX( 1, P )
 | |
|          ITAUQ1 = ITAUP2 + MAX( 1, M-P )
 | |
|          IORBDB = ITAUQ1 + MAX( 1, Q )
 | |
|          IORGQR = ITAUQ1 + MAX( 1, Q )
 | |
|          IORGLQ = ITAUQ1 + MAX( 1, Q )
 | |
|          LORGQRMIN = 1
 | |
|          LORGQROPT = 1
 | |
|          LORGLQMIN = 1
 | |
|          LORGLQOPT = 1
 | |
|          IF( R .EQ. Q ) THEN
 | |
|             CALL SORBDB1( M, P, Q, X11, LDX11, X21, LDX21, THETA,
 | |
|      $                    DUM1, DUM1, DUM1, DUM1, WORK, -1,
 | |
|      $                    CHILDINFO )
 | |
|             LORBDB = INT( WORK(1) )
 | |
|             IF( WANTU1 .AND. P .GT. 0 ) THEN
 | |
|                CALL SORGQR( P, P, Q, U1, LDU1, DUM1, WORK(1), -1,
 | |
|      $                      CHILDINFO )
 | |
|                LORGQRMIN = MAX( LORGQRMIN, P )
 | |
|                LORGQROPT = MAX( LORGQROPT, INT( WORK(1) ) )
 | |
|             ENDIF
 | |
|             IF( WANTU2 .AND. M-P .GT. 0 ) THEN
 | |
|                CALL SORGQR( M-P, M-P, Q, U2, LDU2, DUM1, WORK(1), -1,
 | |
|      $                      CHILDINFO )
 | |
|                LORGQRMIN = MAX( LORGQRMIN, M-P )
 | |
|                LORGQROPT = MAX( LORGQROPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             IF( WANTV1T .AND. Q .GT. 0 ) THEN
 | |
|                CALL SORGLQ( Q-1, Q-1, Q-1, V1T, LDV1T,
 | |
|      $                      DUM1, WORK(1), -1, CHILDINFO )
 | |
|                LORGLQMIN = MAX( LORGLQMIN, Q-1 )
 | |
|                LORGLQOPT = MAX( LORGLQOPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             CALL SBBCSD( JOBU1, JOBU2, JOBV1T, 'N', 'N', M, P, Q, THETA,
 | |
|      $                   DUM1, U1, LDU1, U2, LDU2, V1T, LDV1T, DUM2,
 | |
|      $                   1, DUM1, DUM1, DUM1, DUM1, DUM1,
 | |
|      $                   DUM1, DUM1, DUM1, WORK(1), -1, CHILDINFO
 | |
|      $                 )
 | |
|             LBBCSD = INT( WORK(1) )
 | |
|          ELSE IF( R .EQ. P ) THEN
 | |
|             CALL SORBDB2( M, P, Q, X11, LDX11, X21, LDX21, THETA,
 | |
|      $                    DUM1, DUM1, DUM1, DUM1, WORK(1), -1,
 | |
|      $                    CHILDINFO )
 | |
|             LORBDB = INT( WORK(1) )
 | |
|             IF( WANTU1 .AND. P .GT. 0 ) THEN
 | |
|                CALL SORGQR( P-1, P-1, P-1, U1(2,2), LDU1, DUM1,
 | |
|      $                      WORK(1), -1, CHILDINFO )
 | |
|                LORGQRMIN = MAX( LORGQRMIN, P-1 )
 | |
|                LORGQROPT = MAX( LORGQROPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             IF( WANTU2 .AND. M-P .GT. 0 ) THEN
 | |
|                CALL SORGQR( M-P, M-P, Q, U2, LDU2, DUM1, WORK(1), -1,
 | |
|      $                      CHILDINFO )
 | |
|                LORGQRMIN = MAX( LORGQRMIN, M-P )
 | |
|                LORGQROPT = MAX( LORGQROPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             IF( WANTV1T .AND. Q .GT. 0 ) THEN
 | |
|                CALL SORGLQ( Q, Q, R, V1T, LDV1T, DUM1, WORK(1), -1,
 | |
|      $                      CHILDINFO )
 | |
|                LORGLQMIN = MAX( LORGLQMIN, Q )
 | |
|                LORGLQOPT = MAX( LORGLQOPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             CALL SBBCSD( JOBV1T, 'N', JOBU1, JOBU2, 'T', M, Q, P, THETA,
 | |
|      $                   DUM1, V1T, LDV1T, DUM2, 1, U1, LDU1, U2,
 | |
|      $                   LDU2, DUM1, DUM1, DUM1, DUM1, DUM1,
 | |
|      $                   DUM1, DUM1, DUM1, WORK(1), -1, CHILDINFO
 | |
|      $                 )
 | |
|             LBBCSD = INT( WORK(1) )
 | |
|          ELSE IF( R .EQ. M-P ) THEN
 | |
|             CALL SORBDB3( M, P, Q, X11, LDX11, X21, LDX21, THETA,
 | |
|      $                    DUM1, DUM1, DUM1, DUM1, WORK(1), -1,
 | |
|      $                    CHILDINFO )
 | |
|             LORBDB = INT( WORK(1) )
 | |
|             IF( WANTU1 .AND. P .GT. 0 ) THEN
 | |
|                CALL SORGQR( P, P, Q, U1, LDU1, DUM1, WORK(1), -1,
 | |
|      $                      CHILDINFO )
 | |
|                LORGQRMIN = MAX( LORGQRMIN, P )
 | |
|                LORGQROPT = MAX( LORGQROPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             IF( WANTU2 .AND. M-P .GT. 0 ) THEN
 | |
|                CALL SORGQR( M-P-1, M-P-1, M-P-1, U2(2,2), LDU2, DUM1,
 | |
|      $                      WORK(1), -1, CHILDINFO )
 | |
|                LORGQRMIN = MAX( LORGQRMIN, M-P-1 )
 | |
|                LORGQROPT = MAX( LORGQROPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             IF( WANTV1T .AND. Q .GT. 0 ) THEN
 | |
|                CALL SORGLQ( Q, Q, R, V1T, LDV1T, DUM1, WORK(1), -1,
 | |
|      $                      CHILDINFO )
 | |
|                LORGLQMIN = MAX( LORGLQMIN, Q )
 | |
|                LORGLQOPT = MAX( LORGLQOPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             CALL SBBCSD( 'N', JOBV1T, JOBU2, JOBU1, 'T', M, M-Q, M-P,
 | |
|      $                   THETA, DUM1, DUM2, 1, V1T, LDV1T, U2, LDU2,
 | |
|      $                   U1, LDU1, DUM1, DUM1, DUM1, DUM1,
 | |
|      $                   DUM1, DUM1, DUM1, DUM1, WORK(1), -1,
 | |
|      $                   CHILDINFO )
 | |
|             LBBCSD = INT( WORK(1) )
 | |
|          ELSE
 | |
|             CALL SORBDB4( M, P, Q, X11, LDX11, X21, LDX21, THETA,
 | |
|      $                    DUM1, DUM1, DUM1, DUM1, DUM1,
 | |
|      $                    WORK(1), -1, CHILDINFO )
 | |
|             LORBDB = M + INT( WORK(1) )
 | |
|             IF( WANTU1 .AND. P .GT. 0 ) THEN
 | |
|                CALL SORGQR( P, P, M-Q, U1, LDU1, DUM1, WORK(1), -1,
 | |
|      $                      CHILDINFO )
 | |
|                LORGQRMIN = MAX( LORGQRMIN, P )
 | |
|                LORGQROPT = MAX( LORGQROPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             IF( WANTU2 .AND. M-P .GT. 0 ) THEN
 | |
|                CALL SORGQR( M-P, M-P, M-Q, U2, LDU2, DUM1, WORK(1),
 | |
|      $                      -1, CHILDINFO )
 | |
|                LORGQRMIN = MAX( LORGQRMIN, M-P )
 | |
|                LORGQROPT = MAX( LORGQROPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             IF( WANTV1T .AND. Q .GT. 0 ) THEN
 | |
|                CALL SORGLQ( Q, Q, Q, V1T, LDV1T, DUM1, WORK(1), -1,
 | |
|      $                      CHILDINFO )
 | |
|                LORGLQMIN = MAX( LORGLQMIN, Q )
 | |
|                LORGLQOPT = MAX( LORGLQOPT, INT( WORK(1) ) )
 | |
|             END IF
 | |
|             CALL SBBCSD( JOBU2, JOBU1, 'N', JOBV1T, 'N', M, M-P, M-Q,
 | |
|      $                   THETA, DUM1, U2, LDU2, U1, LDU1, DUM2, 1,
 | |
|      $                   V1T, LDV1T, DUM1, DUM1, DUM1, DUM1,
 | |
|      $                   DUM1, DUM1, DUM1, DUM1, WORK(1), -1,
 | |
|      $                   CHILDINFO )
 | |
|             LBBCSD = INT( WORK(1) )
 | |
|          END IF
 | |
|          LWORKMIN = MAX( IORBDB+LORBDB-1,
 | |
|      $                   IORGQR+LORGQRMIN-1,
 | |
|      $                   IORGLQ+LORGLQMIN-1,
 | |
|      $                   IBBCSD+LBBCSD-1 )
 | |
|          LWORKOPT = MAX( IORBDB+LORBDB-1,
 | |
|      $                   IORGQR+LORGQROPT-1,
 | |
|      $                   IORGLQ+LORGLQOPT-1,
 | |
|      $                   IBBCSD+LBBCSD-1 )
 | |
|          WORK(1) = LWORKOPT
 | |
|          IF( LWORK .LT. LWORKMIN .AND. .NOT.LQUERY ) THEN
 | |
|             INFO = -19
 | |
|          END IF
 | |
|       END IF
 | |
|       IF( INFO .NE. 0 ) THEN
 | |
|          CALL XERBLA( 'SORCSD2BY1', -INFO )
 | |
|          RETURN
 | |
|       ELSE IF( LQUERY ) THEN
 | |
|          RETURN
 | |
|       END IF
 | |
|       LORGQR = LWORK-IORGQR+1
 | |
|       LORGLQ = LWORK-IORGLQ+1
 | |
| *
 | |
| *     Handle four cases separately: R = Q, R = P, R = M-P, and R = M-Q,
 | |
| *     in which R = MIN(P,M-P,Q,M-Q)
 | |
| *
 | |
|       IF( R .EQ. Q ) THEN
 | |
| *
 | |
| *        Case 1: R = Q
 | |
| *
 | |
| *        Simultaneously bidiagonalize X11 and X21
 | |
| *
 | |
|          CALL SORBDB1( M, P, Q, X11, LDX11, X21, LDX21, THETA,
 | |
|      $                 WORK(IPHI), WORK(ITAUP1), WORK(ITAUP2),
 | |
|      $                 WORK(ITAUQ1), WORK(IORBDB), LORBDB, CHILDINFO )
 | |
| *
 | |
| *        Accumulate Householder reflectors
 | |
| *
 | |
|          IF( WANTU1 .AND. P .GT. 0 ) THEN
 | |
|             CALL SLACPY( 'L', P, Q, X11, LDX11, U1, LDU1 )
 | |
|             CALL SORGQR( P, P, Q, U1, LDU1, WORK(ITAUP1), WORK(IORGQR),
 | |
|      $                   LORGQR, CHILDINFO )
 | |
|          END IF
 | |
|          IF( WANTU2 .AND. M-P .GT. 0 ) THEN
 | |
|             CALL SLACPY( 'L', M-P, Q, X21, LDX21, U2, LDU2 )
 | |
|             CALL SORGQR( M-P, M-P, Q, U2, LDU2, WORK(ITAUP2),
 | |
|      $                   WORK(IORGQR), LORGQR, CHILDINFO )
 | |
|          END IF
 | |
|          IF( WANTV1T .AND. Q .GT. 0 ) THEN
 | |
|             V1T(1,1) = ONE
 | |
|             DO J = 2, Q
 | |
|                V1T(1,J) = ZERO
 | |
|                V1T(J,1) = ZERO
 | |
|             END DO
 | |
|             CALL SLACPY( 'U', Q-1, Q-1, X21(1,2), LDX21, V1T(2,2),
 | |
|      $                   LDV1T )
 | |
|             CALL SORGLQ( Q-1, Q-1, Q-1, V1T(2,2), LDV1T, WORK(ITAUQ1),
 | |
|      $                   WORK(IORGLQ), LORGLQ, CHILDINFO )
 | |
|          END IF
 | |
| *
 | |
| *        Simultaneously diagonalize X11 and X21.
 | |
| *
 | |
|          CALL SBBCSD( JOBU1, JOBU2, JOBV1T, 'N', 'N', M, P, Q, THETA,
 | |
|      $                WORK(IPHI), U1, LDU1, U2, LDU2, V1T, LDV1T,
 | |
|      $                DUM2, 1, WORK(IB11D), WORK(IB11E), WORK(IB12D),
 | |
|      $                WORK(IB12E), WORK(IB21D), WORK(IB21E),
 | |
|      $                WORK(IB22D), WORK(IB22E), WORK(IBBCSD), LBBCSD,
 | |
|      $                CHILDINFO )
 | |
| *
 | |
| *        Permute rows and columns to place zero submatrices in
 | |
| *        preferred positions
 | |
| *
 | |
|          IF( Q .GT. 0 .AND. WANTU2 ) THEN
 | |
|             DO I = 1, Q
 | |
|                IWORK(I) = M - P - Q + I
 | |
|             END DO
 | |
|             DO I = Q + 1, M - P
 | |
|                IWORK(I) = I - Q
 | |
|             END DO
 | |
|             CALL SLAPMT( .FALSE., M-P, M-P, U2, LDU2, IWORK )
 | |
|          END IF
 | |
|       ELSE IF( R .EQ. P ) THEN
 | |
| *
 | |
| *        Case 2: R = P
 | |
| *
 | |
| *        Simultaneously bidiagonalize X11 and X21
 | |
| *
 | |
|          CALL SORBDB2( M, P, Q, X11, LDX11, X21, LDX21, THETA,
 | |
|      $                 WORK(IPHI), WORK(ITAUP1), WORK(ITAUP2),
 | |
|      $                 WORK(ITAUQ1), WORK(IORBDB), LORBDB, CHILDINFO )
 | |
| *
 | |
| *        Accumulate Householder reflectors
 | |
| *
 | |
|          IF( WANTU1 .AND. P .GT. 0 ) THEN
 | |
|             U1(1,1) = ONE
 | |
|             DO J = 2, P
 | |
|                U1(1,J) = ZERO
 | |
|                U1(J,1) = ZERO
 | |
|             END DO
 | |
|             CALL SLACPY( 'L', P-1, P-1, X11(2,1), LDX11, U1(2,2), LDU1 )
 | |
|             CALL SORGQR( P-1, P-1, P-1, U1(2,2), LDU1, WORK(ITAUP1),
 | |
|      $                   WORK(IORGQR), LORGQR, CHILDINFO )
 | |
|          END IF
 | |
|          IF( WANTU2 .AND. M-P .GT. 0 ) THEN
 | |
|             CALL SLACPY( 'L', M-P, Q, X21, LDX21, U2, LDU2 )
 | |
|             CALL SORGQR( M-P, M-P, Q, U2, LDU2, WORK(ITAUP2),
 | |
|      $                   WORK(IORGQR), LORGQR, CHILDINFO )
 | |
|          END IF
 | |
|          IF( WANTV1T .AND. Q .GT. 0 ) THEN
 | |
|             CALL SLACPY( 'U', P, Q, X11, LDX11, V1T, LDV1T )
 | |
|             CALL SORGLQ( Q, Q, R, V1T, LDV1T, WORK(ITAUQ1),
 | |
|      $                   WORK(IORGLQ), LORGLQ, CHILDINFO )
 | |
|          END IF
 | |
| *
 | |
| *        Simultaneously diagonalize X11 and X21.
 | |
| *
 | |
|          CALL SBBCSD( JOBV1T, 'N', JOBU1, JOBU2, 'T', M, Q, P, THETA,
 | |
|      $                WORK(IPHI), V1T, LDV1T, DUM1, 1, U1, LDU1, U2,
 | |
|      $                LDU2, WORK(IB11D), WORK(IB11E), WORK(IB12D),
 | |
|      $                WORK(IB12E), WORK(IB21D), WORK(IB21E),
 | |
|      $                WORK(IB22D), WORK(IB22E), WORK(IBBCSD), LBBCSD,
 | |
|      $                CHILDINFO )
 | |
| *
 | |
| *        Permute rows and columns to place identity submatrices in
 | |
| *        preferred positions
 | |
| *
 | |
|          IF( Q .GT. 0 .AND. WANTU2 ) THEN
 | |
|             DO I = 1, Q
 | |
|                IWORK(I) = M - P - Q + I
 | |
|             END DO
 | |
|             DO I = Q + 1, M - P
 | |
|                IWORK(I) = I - Q
 | |
|             END DO
 | |
|             CALL SLAPMT( .FALSE., M-P, M-P, U2, LDU2, IWORK )
 | |
|          END IF
 | |
|       ELSE IF( R .EQ. M-P ) THEN
 | |
| *
 | |
| *        Case 3: R = M-P
 | |
| *
 | |
| *        Simultaneously bidiagonalize X11 and X21
 | |
| *
 | |
|          CALL SORBDB3( M, P, Q, X11, LDX11, X21, LDX21, THETA,
 | |
|      $                 WORK(IPHI), WORK(ITAUP1), WORK(ITAUP2),
 | |
|      $                 WORK(ITAUQ1), WORK(IORBDB), LORBDB, CHILDINFO )
 | |
| *
 | |
| *        Accumulate Householder reflectors
 | |
| *
 | |
|          IF( WANTU1 .AND. P .GT. 0 ) THEN
 | |
|             CALL SLACPY( 'L', P, Q, X11, LDX11, U1, LDU1 )
 | |
|             CALL SORGQR( P, P, Q, U1, LDU1, WORK(ITAUP1), WORK(IORGQR),
 | |
|      $                   LORGQR, CHILDINFO )
 | |
|          END IF
 | |
|          IF( WANTU2 .AND. M-P .GT. 0 ) THEN
 | |
|             U2(1,1) = ONE
 | |
|             DO J = 2, M-P
 | |
|                U2(1,J) = ZERO
 | |
|                U2(J,1) = ZERO
 | |
|             END DO
 | |
|             CALL SLACPY( 'L', M-P-1, M-P-1, X21(2,1), LDX21, U2(2,2),
 | |
|      $                   LDU2 )
 | |
|             CALL SORGQR( M-P-1, M-P-1, M-P-1, U2(2,2), LDU2,
 | |
|      $                   WORK(ITAUP2), WORK(IORGQR), LORGQR, CHILDINFO )
 | |
|          END IF
 | |
|          IF( WANTV1T .AND. Q .GT. 0 ) THEN
 | |
|             CALL SLACPY( 'U', M-P, Q, X21, LDX21, V1T, LDV1T )
 | |
|             CALL SORGLQ( Q, Q, R, V1T, LDV1T, WORK(ITAUQ1),
 | |
|      $                   WORK(IORGLQ), LORGLQ, CHILDINFO )
 | |
|          END IF
 | |
| *
 | |
| *        Simultaneously diagonalize X11 and X21.
 | |
| *
 | |
|          CALL SBBCSD( 'N', JOBV1T, JOBU2, JOBU1, 'T', M, M-Q, M-P,
 | |
|      $                THETA, WORK(IPHI), DUM1, 1, V1T, LDV1T, U2,
 | |
|      $                LDU2, U1, LDU1, WORK(IB11D), WORK(IB11E),
 | |
|      $                WORK(IB12D), WORK(IB12E), WORK(IB21D),
 | |
|      $                WORK(IB21E), WORK(IB22D), WORK(IB22E),
 | |
|      $                WORK(IBBCSD), LBBCSD, CHILDINFO )
 | |
| *
 | |
| *        Permute rows and columns to place identity submatrices in
 | |
| *        preferred positions
 | |
| *
 | |
|          IF( Q .GT. R ) THEN
 | |
|             DO I = 1, R
 | |
|                IWORK(I) = Q - R + I
 | |
|             END DO
 | |
|             DO I = R + 1, Q
 | |
|                IWORK(I) = I - R
 | |
|             END DO
 | |
|             IF( WANTU1 ) THEN
 | |
|                CALL SLAPMT( .FALSE., P, Q, U1, LDU1, IWORK )
 | |
|             END IF
 | |
|             IF( WANTV1T ) THEN
 | |
|                CALL SLAPMR( .FALSE., Q, Q, V1T, LDV1T, IWORK )
 | |
|             END IF
 | |
|          END IF
 | |
|       ELSE
 | |
| *
 | |
| *        Case 4: R = M-Q
 | |
| *
 | |
| *        Simultaneously bidiagonalize X11 and X21
 | |
| *
 | |
|          CALL SORBDB4( M, P, Q, X11, LDX11, X21, LDX21, THETA,
 | |
|      $                 WORK(IPHI), WORK(ITAUP1), WORK(ITAUP2),
 | |
|      $                 WORK(ITAUQ1), WORK(IORBDB), WORK(IORBDB+M),
 | |
|      $                 LORBDB-M, CHILDINFO )
 | |
| *
 | |
| *        Accumulate Householder reflectors
 | |
| *
 | |
|          IF( WANTU1 .AND. P .GT. 0 ) THEN
 | |
|             CALL SCOPY( P, WORK(IORBDB), 1, U1, 1 )
 | |
|             DO J = 2, P
 | |
|                U1(1,J) = ZERO
 | |
|             END DO
 | |
|             CALL SLACPY( 'L', P-1, M-Q-1, X11(2,1), LDX11, U1(2,2),
 | |
|      $                   LDU1 )
 | |
|             CALL SORGQR( P, P, M-Q, U1, LDU1, WORK(ITAUP1),
 | |
|      $                   WORK(IORGQR), LORGQR, CHILDINFO )
 | |
|          END IF
 | |
|          IF( WANTU2 .AND. M-P .GT. 0 ) THEN
 | |
|             CALL SCOPY( M-P, WORK(IORBDB+P), 1, U2, 1 )
 | |
|             DO J = 2, M-P
 | |
|                U2(1,J) = ZERO
 | |
|             END DO
 | |
|             CALL SLACPY( 'L', M-P-1, M-Q-1, X21(2,1), LDX21, U2(2,2),
 | |
|      $                   LDU2 )
 | |
|             CALL SORGQR( M-P, M-P, M-Q, U2, LDU2, WORK(ITAUP2),
 | |
|      $                   WORK(IORGQR), LORGQR, CHILDINFO )
 | |
|          END IF
 | |
|          IF( WANTV1T .AND. Q .GT. 0 ) THEN
 | |
|             CALL SLACPY( 'U', M-Q, Q, X21, LDX21, V1T, LDV1T )
 | |
|             CALL SLACPY( 'U', P-(M-Q), Q-(M-Q), X11(M-Q+1,M-Q+1), LDX11,
 | |
|      $                   V1T(M-Q+1,M-Q+1), LDV1T )
 | |
|             CALL SLACPY( 'U', -P+Q, Q-P, X21(M-Q+1,P+1), LDX21,
 | |
|      $                   V1T(P+1,P+1), LDV1T )
 | |
|             CALL SORGLQ( Q, Q, Q, V1T, LDV1T, WORK(ITAUQ1),
 | |
|      $                   WORK(IORGLQ), LORGLQ, CHILDINFO )
 | |
|          END IF
 | |
| *
 | |
| *        Simultaneously diagonalize X11 and X21.
 | |
| *
 | |
|          CALL SBBCSD( JOBU2, JOBU1, 'N', JOBV1T, 'N', M, M-P, M-Q,
 | |
|      $                THETA, WORK(IPHI), U2, LDU2, U1, LDU1, DUM1, 1,
 | |
|      $                V1T, LDV1T, WORK(IB11D), WORK(IB11E), WORK(IB12D),
 | |
|      $                WORK(IB12E), WORK(IB21D), WORK(IB21E),
 | |
|      $                WORK(IB22D), WORK(IB22E), WORK(IBBCSD), LBBCSD,
 | |
|      $                CHILDINFO )
 | |
| *
 | |
| *        Permute rows and columns to place identity submatrices in
 | |
| *        preferred positions
 | |
| *
 | |
|          IF( P .GT. R ) THEN
 | |
|             DO I = 1, R
 | |
|                IWORK(I) = P - R + I
 | |
|             END DO
 | |
|             DO I = R + 1, P
 | |
|                IWORK(I) = I - R
 | |
|             END DO
 | |
|             IF( WANTU1 ) THEN
 | |
|                CALL SLAPMT( .FALSE., P, P, U1, LDU1, IWORK )
 | |
|             END IF
 | |
|             IF( WANTV1T ) THEN
 | |
|                CALL SLAPMR( .FALSE., P, Q, V1T, LDV1T, IWORK )
 | |
|             END IF
 | |
|          END IF
 | |
|       END IF
 | |
| *
 | |
|       RETURN
 | |
| *
 | |
| *     End of SORCSD2BY1
 | |
| *
 | |
|       END
 | |
| 
 |