--- rpl/lapack/lapack/zggsvd.f 2011/07/22 07:38:14 1.8 +++ rpl/lapack/lapack/zggsvd.f 2011/11/21 20:43:10 1.9 @@ -1,11 +1,344 @@ +*> \brief ZGGSVD computes the singular value decomposition (SVD) for OTHER matrices +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download ZGGSVD + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE ZGGSVD( JOBU, JOBV, JOBQ, M, N, P, K, L, A, LDA, B, +* LDB, ALPHA, BETA, U, LDU, V, LDV, Q, LDQ, WORK, +* RWORK, IWORK, INFO ) +* +* .. Scalar Arguments .. +* CHARACTER JOBQ, JOBU, JOBV +* INTEGER INFO, K, L, LDA, LDB, LDQ, LDU, LDV, M, N, P +* .. +* .. Array Arguments .. +* INTEGER IWORK( * ) +* DOUBLE PRECISION ALPHA( * ), BETA( * ), RWORK( * ) +* COMPLEX*16 A( LDA, * ), B( LDB, * ), Q( LDQ, * ), +* $ U( LDU, * ), V( LDV, * ), WORK( * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> ZGGSVD computes the generalized singular value decomposition (GSVD) +*> of an M-by-N complex matrix A and P-by-N complex matrix B: +*> +*> U**H*A*Q = D1*( 0 R ), V**H*B*Q = D2*( 0 R ) +*> +*> where U, V and Q are unitary matrices. +*> Let K+L = the effective numerical rank of the +*> matrix (A**H,B**H)**H, then R is a (K+L)-by-(K+L) nonsingular upper +*> triangular matrix, D1 and D2 are M-by-(K+L) and P-by-(K+L) "diagonal" +*> matrices and of the following structures, respectively: +*> +*> If M-K-L >= 0, +*> +*> K L +*> D1 = K ( I 0 ) +*> L ( 0 C ) +*> M-K-L ( 0 0 ) +*> +*> K L +*> D2 = L ( 0 S ) +*> P-L ( 0 0 ) +*> +*> N-K-L K L +*> ( 0 R ) = K ( 0 R11 R12 ) +*> L ( 0 0 R22 ) +*> where +*> +*> C = diag( ALPHA(K+1), ... , ALPHA(K+L) ), +*> S = diag( BETA(K+1), ... , BETA(K+L) ), +*> C**2 + S**2 = I. +*> +*> R is stored in A(1:K+L,N-K-L+1:N) on exit. +*> +*> If M-K-L < 0, +*> +*> K M-K K+L-M +*> D1 = K ( I 0 0 ) +*> M-K ( 0 C 0 ) +*> +*> K M-K K+L-M +*> D2 = M-K ( 0 S 0 ) +*> K+L-M ( 0 0 I ) +*> P-L ( 0 0 0 ) +*> +*> N-K-L K M-K K+L-M +*> ( 0 R ) = K ( 0 R11 R12 R13 ) +*> M-K ( 0 0 R22 R23 ) +*> K+L-M ( 0 0 0 R33 ) +*> +*> where +*> +*> C = diag( ALPHA(K+1), ... , ALPHA(M) ), +*> S = diag( BETA(K+1), ... , BETA(M) ), +*> C**2 + S**2 = I. +*> +*> (R11 R12 R13 ) is stored in A(1:M, N-K-L+1:N), and R33 is stored +*> ( 0 R22 R23 ) +*> in B(M-K+1:L,N+M-K-L+1:N) on exit. +*> +*> The routine computes C, S, R, and optionally the unitary +*> transformation matrices U, V and Q. +*> +*> In particular, if B is an N-by-N nonsingular matrix, then the GSVD of +*> A and B implicitly gives the SVD of A*inv(B): +*> A*inv(B) = U*(D1*inv(D2))*V**H. +*> If ( A**H,B**H)**H has orthnormal columns, then the GSVD of A and B is also +*> equal to the CS decomposition of A and B. Furthermore, the GSVD can +*> be used to derive the solution of the eigenvalue problem: +*> A**H*A x = lambda* B**H*B x. +*> In some literature, the GSVD of A and B is presented in the form +*> U**H*A*X = ( 0 D1 ), V**H*B*X = ( 0 D2 ) +*> where U and V are orthogonal and X is nonsingular, and D1 and D2 are +*> ``diagonal''. The former GSVD form can be converted to the latter +*> form by taking the nonsingular matrix X as +*> +*> X = Q*( I 0 ) +*> ( 0 inv(R) ) +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] JOBU +*> \verbatim +*> JOBU is CHARACTER*1 +*> = 'U': Unitary matrix U is computed; +*> = 'N': U is not computed. +*> \endverbatim +*> +*> \param[in] JOBV +*> \verbatim +*> JOBV is CHARACTER*1 +*> = 'V': Unitary matrix V is computed; +*> = 'N': V is not computed. +*> \endverbatim +*> +*> \param[in] JOBQ +*> \verbatim +*> JOBQ is CHARACTER*1 +*> = 'Q': Unitary matrix Q is computed; +*> = 'N': Q is not computed. +*> \endverbatim +*> +*> \param[in] M +*> \verbatim +*> M is INTEGER +*> The number of rows of the matrix A. M >= 0. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The number of columns of the matrices A and B. N >= 0. +*> \endverbatim +*> +*> \param[in] P +*> \verbatim +*> P is INTEGER +*> The number of rows of the matrix B. P >= 0. +*> \endverbatim +*> +*> \param[out] K +*> \verbatim +*> K is INTEGER +*> \endverbatim +*> +*> \param[out] L +*> \verbatim +*> L is INTEGER +*> +*> On exit, K and L specify the dimension of the subblocks +*> described in Purpose. +*> K + L = effective numerical rank of (A**H,B**H)**H. +*> \endverbatim +*> +*> \param[in,out] A +*> \verbatim +*> A is COMPLEX*16 array, dimension (LDA,N) +*> On entry, the M-by-N matrix A. +*> On exit, A contains the triangular matrix R, or part of R. +*> See Purpose for details. +*> \endverbatim +*> +*> \param[in] LDA +*> \verbatim +*> LDA is INTEGER +*> The leading dimension of the array A. LDA >= max(1,M). +*> \endverbatim +*> +*> \param[in,out] B +*> \verbatim +*> B is COMPLEX*16 array, dimension (LDB,N) +*> On entry, the P-by-N matrix B. +*> On exit, B contains part of the triangular matrix R if +*> M-K-L < 0. See Purpose for details. +*> \endverbatim +*> +*> \param[in] LDB +*> \verbatim +*> LDB is INTEGER +*> The leading dimension of the array B. LDB >= max(1,P). +*> \endverbatim +*> +*> \param[out] ALPHA +*> \verbatim +*> ALPHA is DOUBLE PRECISION array, dimension (N) +*> \endverbatim +*> +*> \param[out] BETA +*> \verbatim +*> BETA is DOUBLE PRECISION array, dimension (N) +*> +*> On exit, ALPHA and BETA contain the generalized singular +*> value pairs of A and B; +*> ALPHA(1:K) = 1, +*> BETA(1:K) = 0, +*> and if M-K-L >= 0, +*> ALPHA(K+1:K+L) = C, +*> BETA(K+1:K+L) = S, +*> or if M-K-L < 0, +*> ALPHA(K+1:M)=C, ALPHA(M+1:K+L)=0 +*> BETA(K+1:M) =S, BETA(M+1:K+L) =1 +*> and +*> ALPHA(K+L+1:N) = 0 +*> BETA(K+L+1:N) = 0 +*> \endverbatim +*> +*> \param[out] U +*> \verbatim +*> U is COMPLEX*16 array, dimension (LDU,M) +*> If JOBU = 'U', U contains the M-by-M unitary matrix U. +*> If JOBU = 'N', U is not referenced. +*> \endverbatim +*> +*> \param[in] LDU +*> \verbatim +*> LDU is INTEGER +*> The leading dimension of the array U. LDU >= max(1,M) if +*> JOBU = 'U'; LDU >= 1 otherwise. +*> \endverbatim +*> +*> \param[out] V +*> \verbatim +*> V is COMPLEX*16 array, dimension (LDV,P) +*> If JOBV = 'V', V contains the P-by-P unitary matrix V. +*> If JOBV = 'N', V is not referenced. +*> \endverbatim +*> +*> \param[in] LDV +*> \verbatim +*> LDV is INTEGER +*> The leading dimension of the array V. LDV >= max(1,P) if +*> JOBV = 'V'; LDV >= 1 otherwise. +*> \endverbatim +*> +*> \param[out] Q +*> \verbatim +*> Q is COMPLEX*16 array, dimension (LDQ,N) +*> If JOBQ = 'Q', Q contains the N-by-N unitary matrix Q. +*> If JOBQ = 'N', Q is not referenced. +*> \endverbatim +*> +*> \param[in] LDQ +*> \verbatim +*> LDQ is INTEGER +*> The leading dimension of the array Q. LDQ >= max(1,N) if +*> JOBQ = 'Q'; LDQ >= 1 otherwise. +*> \endverbatim +*> +*> \param[out] WORK +*> \verbatim +*> WORK is COMPLEX*16 array, dimension (max(3*N,M,P)+N) +*> \endverbatim +*> +*> \param[out] RWORK +*> \verbatim +*> RWORK is DOUBLE PRECISION array, dimension (2*N) +*> \endverbatim +*> +*> \param[out] IWORK +*> \verbatim +*> IWORK is INTEGER array, dimension (N) +*> On exit, IWORK stores the sorting information. More +*> precisely, the following loop will sort ALPHA +*> for I = K+1, min(M,K+L) +*> swap ALPHA(I) and ALPHA(IWORK(I)) +*> endfor +*> such that ALPHA(1) >= ALPHA(2) >= ... >= ALPHA(N). +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit. +*> < 0: if INFO = -i, the i-th argument had an illegal value. +*> > 0: if INFO = 1, the Jacobi-type procedure failed to +*> converge. For further details, see subroutine ZTGSJA. +*> \endverbatim +* +*> \par Internal Parameters: +* ========================= +*> +*> \verbatim +*> TOLA DOUBLE PRECISION +*> TOLB DOUBLE PRECISION +*> TOLA and TOLB are the thresholds to determine the effective +*> rank of (A**H,B**H)**H. 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. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2011 +* +*> \ingroup complex16OTHERsing +* +*> \par Contributors: +* ================== +*> +*> Ming Gu and Huan Ren, Computer Science Division, University of +*> California at Berkeley, USA +*> +* ===================================================================== SUBROUTINE ZGGSVD( JOBU, JOBV, JOBQ, M, N, P, K, L, A, LDA, B, $ LDB, ALPHA, BETA, U, LDU, V, LDV, Q, LDQ, WORK, $ RWORK, IWORK, INFO ) * -* -- LAPACK driver routine (version 3.3.1) -- +* -- LAPACK driver routine (version 3.4.0) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* -- April 2011 -- +* November 2011 * * .. Scalar Arguments .. CHARACTER JOBQ, JOBU, JOBV @@ -18,210 +351,6 @@ $ U( LDU, * ), V( LDV, * ), WORK( * ) * .. * -* Purpose -* ======= -* -* ZGGSVD computes the generalized singular value decomposition (GSVD) -* of an M-by-N complex matrix A and P-by-N complex matrix B: -* -* U**H*A*Q = D1*( 0 R ), V**H*B*Q = D2*( 0 R ) -* -* where U, V and Q are unitary matrices. -* Let K+L = the effective numerical rank of the -* matrix (A**H,B**H)**H, then R is a (K+L)-by-(K+L) nonsingular upper -* triangular matrix, D1 and D2 are M-by-(K+L) and P-by-(K+L) "diagonal" -* matrices and of the following structures, respectively: -* -* If M-K-L >= 0, -* -* K L -* D1 = K ( I 0 ) -* L ( 0 C ) -* M-K-L ( 0 0 ) -* -* K L -* D2 = L ( 0 S ) -* P-L ( 0 0 ) -* -* N-K-L K L -* ( 0 R ) = K ( 0 R11 R12 ) -* L ( 0 0 R22 ) -* where -* -* C = diag( ALPHA(K+1), ... , ALPHA(K+L) ), -* S = diag( BETA(K+1), ... , BETA(K+L) ), -* C**2 + S**2 = I. -* -* R is stored in A(1:K+L,N-K-L+1:N) on exit. -* -* If M-K-L < 0, -* -* K M-K K+L-M -* D1 = K ( I 0 0 ) -* M-K ( 0 C 0 ) -* -* K M-K K+L-M -* D2 = M-K ( 0 S 0 ) -* K+L-M ( 0 0 I ) -* P-L ( 0 0 0 ) -* -* N-K-L K M-K K+L-M -* ( 0 R ) = K ( 0 R11 R12 R13 ) -* M-K ( 0 0 R22 R23 ) -* K+L-M ( 0 0 0 R33 ) -* -* where -* -* C = diag( ALPHA(K+1), ... , ALPHA(M) ), -* S = diag( BETA(K+1), ... , BETA(M) ), -* C**2 + S**2 = I. -* -* (R11 R12 R13 ) is stored in A(1:M, N-K-L+1:N), and R33 is stored -* ( 0 R22 R23 ) -* in B(M-K+1:L,N+M-K-L+1:N) on exit. -* -* The routine computes C, S, R, and optionally the unitary -* transformation matrices U, V and Q. -* -* In particular, if B is an N-by-N nonsingular matrix, then the GSVD of -* A and B implicitly gives the SVD of A*inv(B): -* A*inv(B) = U*(D1*inv(D2))*V**H. -* If ( A**H,B**H)**H has orthnormal columns, then the GSVD of A and B is also -* equal to the CS decomposition of A and B. Furthermore, the GSVD can -* be used to derive the solution of the eigenvalue problem: -* A**H*A x = lambda* B**H*B x. -* In some literature, the GSVD of A and B is presented in the form -* U**H*A*X = ( 0 D1 ), V**H*B*X = ( 0 D2 ) -* where U and V are orthogonal and X is nonsingular, and D1 and D2 are -* ``diagonal''. The former GSVD form can be converted to the latter -* form by taking the nonsingular matrix X as -* -* X = Q*( I 0 ) -* ( 0 inv(R) ) -* -* 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. -* -* N (input) INTEGER -* The number of columns of the matrices A and B. N >= 0. -* -* P (input) INTEGER -* The number of rows of the matrix B. P >= 0. -* -* K (output) INTEGER -* L (output) INTEGER -* On exit, K and L specify the dimension of the subblocks -* described in Purpose. -* K + L = effective numerical rank of (A**H,B**H)**H. -* -* A (input/output) COMPLEX*16 array, dimension (LDA,N) -* On entry, the M-by-N matrix A. -* On exit, A contains the triangular matrix R, or part of R. -* See Purpose for details. -* -* 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 part of the triangular matrix R if -* M-K-L < 0. See Purpose for details. -* -* LDB (input) INTEGER -* The leading dimension of the array B. LDB >= max(1,P). -* -* ALPHA (output) DOUBLE PRECISION array, dimension (N) -* BETA (output) DOUBLE PRECISION array, dimension (N) -* On exit, ALPHA and BETA contain the generalized singular -* value pairs of A and B; -* ALPHA(1:K) = 1, -* BETA(1:K) = 0, -* and if M-K-L >= 0, -* ALPHA(K+1:K+L) = C, -* BETA(K+1:K+L) = S, -* or if M-K-L < 0, -* ALPHA(K+1:M)= C, ALPHA(M+1:K+L)= 0 -* BETA(K+1:M) = S, BETA(M+1:K+L) = 1 -* and -* ALPHA(K+L+1:N) = 0 -* BETA(K+L+1:N) = 0 -* -* U (output) COMPLEX*16 array, dimension (LDU,M) -* If JOBU = 'U', U contains the M-by-M 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,P) -* If JOBV = 'V', V contains the P-by-P 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 N-by-N 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. -* -* WORK (workspace) COMPLEX*16 array, dimension (max(3*N,M,P)+N) -* -* RWORK (workspace) DOUBLE PRECISION array, dimension (2*N) -* -* IWORK (workspace/output) INTEGER array, dimension (N) -* On exit, IWORK stores the sorting information. More -* precisely, the following loop will sort ALPHA -* for I = K+1, min(M,K+L) -* swap ALPHA(I) and ALPHA(IWORK(I)) -* endfor -* such that ALPHA(1) >= ALPHA(2) >= ... >= ALPHA(N). -* -* INFO (output) INTEGER -* = 0: successful exit. -* < 0: if INFO = -i, the i-th argument had an illegal value. -* > 0: if INFO = 1, the Jacobi-type procedure failed to -* converge. For further details, see subroutine ZTGSJA. -* -* Internal Parameters -* =================== -* -* TOLA DOUBLE PRECISION -* TOLB DOUBLE PRECISION -* TOLA and TOLB are the thresholds to determine the effective -* rank of (A**H,B**H)**H. 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. -* -* Further Details -* =============== -* -* 2-96 Based on modifications by -* Ming Gu and Huan Ren, Computer Science Division, University of -* California at Berkeley, USA -* * ===================================================================== * * .. Local Scalars ..