summaryrefslogtreecommitdiff
path: root/SRC/cbbcsd.f
diff options
context:
space:
mode:
authorjulie <julielangou@users.noreply.github.com>2011-10-06 06:53:11 +0000
committerjulie <julielangou@users.noreply.github.com>2011-10-06 06:53:11 +0000
commite1d39294aee16fa6db9ba079b14442358217db71 (patch)
tree30e5aa04c1f6596991fda5334f63dfb9b8027849 /SRC/cbbcsd.f
parent5fe0466a14e395641f4f8a300ecc9dcb8058081b (diff)
downloadlapack-e1d39294aee16fa6db9ba079b14442358217db71.tar.gz
lapack-e1d39294aee16fa6db9ba079b14442358217db71.tar.bz2
lapack-e1d39294aee16fa6db9ba079b14442358217db71.zip
Integrating Doxygen in comments
Diffstat (limited to 'SRC/cbbcsd.f')
-rw-r--r--SRC/cbbcsd.f464
1 files changed, 293 insertions, 171 deletions
diff --git a/SRC/cbbcsd.f b/SRC/cbbcsd.f
index d5d22101..53881a16 100644
--- a/SRC/cbbcsd.f
+++ b/SRC/cbbcsd.f
@@ -1,16 +1,302 @@
+*> \brief \b CBBCSD
+*
+* =========== DOCUMENTATION ===========
+*
+* Online html documentation available at
+* http://www.netlib.org/lapack/explore-html/
+*
+* Definition
+* ==========
+*
+* SUBROUTINE CBBCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS, M, P, Q,
+* THETA, PHI, U1, LDU1, U2, LDU2, V1T, LDV1T,
+* V2T, LDV2T, B11D, B11E, B12D, B12E, B21D, B21E,
+* B22D, B22E, RWORK, LRWORK, INFO )
+*
+* .. Scalar Arguments ..
+* CHARACTER JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS
+* INTEGER INFO, LDU1, LDU2, LDV1T, LDV2T, LRWORK, M, P, Q
+* ..
+* .. Array Arguments ..
+* REAL B11D( * ), B11E( * ), B12D( * ), B12E( * ),
+* $ B21D( * ), B21E( * ), B22D( * ), B22E( * ),
+* $ PHI( * ), THETA( * ), RWORK( * )
+* COMPLEX U1( LDU1, * ), U2( LDU2, * ), V1T( LDV1T, * ),
+* $ V2T( LDV2T, * )
+* ..
+*
+* Purpose
+* =======
+*
+*>\details \b Purpose:
+*>\verbatim
+*>
+*> CBBCSD computes the CS decomposition of a unitary matrix in
+*> bidiagonal-block form,
+*>
+*>
+*> [ B11 | B12 0 0 ]
+*> [ 0 | 0 -I 0 ]
+*> X = [----------------]
+*> [ B21 | B22 0 0 ]
+*> [ 0 | 0 0 I ]
+*>
+*> [ C | -S 0 0 ]
+*> [ U1 | ] [ 0 | 0 -I 0 ] [ V1 | ]**H
+*> = [---------] [---------------] [---------] .
+*> [ | U2 ] [ S | C 0 0 ] [ | V2 ]
+*> [ 0 | 0 0 I ]
+*>
+*> X is M-by-M, its top-left block is P-by-Q, and Q must be no larger
+*> than P, M-P, or M-Q. (If Q is not the smallest index, then X must be
+*> transposed and/or permuted. This can be done in constant time using
+*> the TRANS and SIGNS options. See CUNCSD for details.)
+*>
+*> The bidiagonal matrices B11, B12, B21, and B22 are represented
+*> implicitly by angles THETA(1:Q) and PHI(1:Q-1).
+*>
+*> The unitary matrices U1, U2, V1T, and V2T are input/output.
+*> The input matrices are pre- or post-multiplied by the appropriate
+*> singular vector matrices.
+*>
+*>\endverbatim
+*
+* Arguments
+* =========
+*
+*> \param[in] JOBU1
+*> \verbatim
+*> JOBU1 is CHARACTER
+*> = 'Y': U1 is updated;
+*> otherwise: U1 is not updated.
+*> \endverbatim
+*>
+*> \param[in] JOBU2
+*> \verbatim
+*> JOBU2 is CHARACTER
+*> = 'Y': U2 is updated;
+*> otherwise: U2 is not updated.
+*> \endverbatim
+*>
+*> \param[in] JOBV1T
+*> \verbatim
+*> JOBV1T is CHARACTER
+*> = 'Y': V1T is updated;
+*> otherwise: V1T is not updated.
+*> \endverbatim
+*>
+*> \param[in] JOBV2T
+*> \verbatim
+*> JOBV2T is CHARACTER
+*> = 'Y': V2T is updated;
+*> otherwise: V2T is not updated.
+*> \endverbatim
+*>
+*> \param[in] TRANS
+*> \verbatim
+*> TRANS is CHARACTER
+*> = 'T': X, U1, U2, V1T, and V2T are stored in row-major
+*> order;
+*> otherwise: X, U1, U2, V1T, and V2T are stored in column-
+*> major order.
+*> \endverbatim
+*>
+*> \param[in] M
+*> \verbatim
+*> M is INTEGER
+*> The number of rows and columns in X, the unitary matrix in
+*> bidiagonal-block form.
+*> \endverbatim
+*>
+*> \param[in] P
+*> \verbatim
+*> P is INTEGER
+*> The number of rows in the top-left block of X. 0 <= P <= M.
+*> \endverbatim
+*>
+*> \param[in] Q
+*> \verbatim
+*> Q is INTEGER
+*> The number of columns in the top-left block of X.
+*> 0 <= Q <= MIN(P,M-P,M-Q).
+*> \endverbatim
+*>
+*> \param[in,out] THETA
+*> \verbatim
+*> THETA is REAL array, dimension (Q)
+*> On entry, the angles THETA(1),...,THETA(Q) that, along with
+*> PHI(1), ...,PHI(Q-1), define the matrix in bidiagonal-block
+*> form. On exit, the angles whose cosines and sines define the
+*> diagonal blocks in the CS decomposition.
+*> \endverbatim
+*>
+*> \param[in,out] PHI
+*> \verbatim
+*> PHI is REAL array, dimension (Q-1)
+*> The angles PHI(1),...,PHI(Q-1) that, along with THETA(1),...,
+*> THETA(Q), define the matrix in bidiagonal-block form.
+*> \endverbatim
+*>
+*> \param[in,out] U1
+*> \verbatim
+*> U1 is COMPLEX array, dimension (LDU1,P)
+*> On entry, an LDU1-by-P matrix. On exit, U1 is postmultiplied
+*> by the left singular vector matrix common to [ B11 ; 0 ] and
+*> [ B12 0 0 ; 0 -I 0 0 ].
+*> \endverbatim
+*>
+*> \param[in] LDU1
+*> \verbatim
+*> LDU1 is INTEGER
+*> The leading dimension of the array U1.
+*> \endverbatim
+*>
+*> \param[in,out] U2
+*> \verbatim
+*> U2 is COMPLEX array, dimension (LDU2,M-P)
+*> On entry, an LDU2-by-(M-P) matrix. On exit, U2 is
+*> postmultiplied by the left singular vector matrix common to
+*> [ B21 ; 0 ] and [ B22 0 0 ; 0 0 I ].
+*> \endverbatim
+*>
+*> \param[in] LDU2
+*> \verbatim
+*> LDU2 is INTEGER
+*> The leading dimension of the array U2.
+*> \endverbatim
+*>
+*> \param[in,out] V1T
+*> \verbatim
+*> V1T is COMPLEX array, dimension (LDV1T,Q)
+*> On entry, a LDV1T-by-Q matrix. On exit, V1T is premultiplied
+*> by the conjugate transpose of the right singular vector
+*> matrix common to [ B11 ; 0 ] and [ B21 ; 0 ].
+*> \endverbatim
+*>
+*> \param[in] LDV1T
+*> \verbatim
+*> LDV1T is INTEGER
+*> The leading dimension of the array V1T.
+*> \endverbatim
+*>
+*> \param[in,out] V2T
+*> \verbatim
+*> V2T is COMPLEX array, dimenison (LDV2T,M-Q)
+*> On entry, a LDV2T-by-(M-Q) matrix. On exit, V2T is
+*> premultiplied by the conjugate transpose of the right
+*> singular vector matrix common to [ B12 0 0 ; 0 -I 0 ] and
+*> [ B22 0 0 ; 0 0 I ].
+*> \endverbatim
+*>
+*> \param[in] LDV2T
+*> \verbatim
+*> LDV2T is INTEGER
+*> The leading dimension of the array V2T.
+*> \endverbatim
+*>
+*> \param[out] B11D
+*> \verbatim
+*> B11D is REAL array, dimension (Q)
+*> When CBBCSD converges, B11D contains the cosines of THETA(1),
+*> ..., THETA(Q). If CBBCSD fails to converge, then B11D
+*> contains the diagonal of the partially reduced top-left
+*> block.
+*> \endverbatim
+*>
+*> \param[out] B11E
+*> \verbatim
+*> B11E is REAL array, dimension (Q-1)
+*> When CBBCSD converges, B11E contains zeros. If CBBCSD fails
+*> to converge, then B11E contains the superdiagonal of the
+*> partially reduced top-left block.
+*> \endverbatim
+*>
+*> \param[out] B12D
+*> \verbatim
+*> B12D is REAL array, dimension (Q)
+*> When CBBCSD converges, B12D contains the negative sines of
+*> THETA(1), ..., THETA(Q). If CBBCSD fails to converge, then
+*> B12D contains the diagonal of the partially reduced top-right
+*> block.
+*> \endverbatim
+*>
+*> \param[out] B12E
+*> \verbatim
+*> B12E is REAL array, dimension (Q-1)
+*> When CBBCSD converges, B12E contains zeros. If CBBCSD fails
+*> to converge, then B12E contains the subdiagonal of the
+*> partially reduced top-right block.
+*> \endverbatim
+*>
+*> \param[out] RWORK
+*> \verbatim
+*> RWORK is REAL array, dimension (MAX(1,LWORK))
+*> On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
+*> \endverbatim
+*>
+*> \param[in] LRWORK
+*> \verbatim
+*> LRWORK is INTEGER
+*> The dimension of the array RWORK. LRWORK >= MAX(1,8*Q).
+*> \endverbatim
+*> \verbatim
+*> If LRWORK = -1, then a workspace query is assumed; the
+*> routine only calculates the optimal size of the RWORK array,
+*> returns this value as the first entry of the work array, and
+*> no error message related to LRWORK is issued by XERBLA.
+*> \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 CBBCSD did not converge, INFO specifies the number
+*> of nonzero entries in PHI, and B11D, B11E, etc.,
+*> contain the partially reduced matrix.
+*> \endverbatim
+*> \verbatim
+*> Reference
+*> =========
+*> \endverbatim
+*> \verbatim
+*> [1] Brian D. Sutton. Computing the complete CS decomposition. Numer.
+*> Algorithms, 50(1):33-65, 2009.
+*> \endverbatim
+*> \verbatim
+*> Internal Parameters
+*> ===================
+*> \endverbatim
+*> \verbatim
+*> TOLMUL REAL, default = MAX(10,MIN(100,EPS**(-1/8)))
+*> TOLMUL controls the convergence criterion of the QR loop.
+*> Angles THETA(i), PHI(i) are rounded to 0 or PI/2 when they
+*> are within TOLMUL*EPS of either bound.
+*> \endverbatim
+*>
+*
+* Authors
+* =======
+*
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
+*
+*> \date November 2011
+*
+*> \ingroup complexOTHERcomputational
+*
+* =====================================================================
SUBROUTINE CBBCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS, M, P, Q,
$ THETA, PHI, U1, LDU1, U2, LDU2, V1T, LDV1T,
$ V2T, LDV2T, B11D, B11E, B12D, B12E, B21D, B21E,
$ B22D, B22E, RWORK, LRWORK, INFO )
- IMPLICIT NONE
-*
-* -- LAPACK routine (version 3.3.0) --
-*
-* -- Contributed by Brian Sutton of the Randolph-Macon College --
-* -- November 2010
*
+* -- LAPACK computational routine (version 3.3.0) --
* -- LAPACK is a software package provided by Univ. of Tennessee, --
-* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
+* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
+* November 2011
*
* .. Scalar Arguments ..
CHARACTER JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS
@@ -24,170 +310,6 @@
$ V2T( LDV2T, * )
* ..
*
-* Purpose
-* =======
-*
-* CBBCSD computes the CS decomposition of a unitary matrix in
-* bidiagonal-block form,
-*
-*
-* [ B11 | B12 0 0 ]
-* [ 0 | 0 -I 0 ]
-* X = [----------------]
-* [ B21 | B22 0 0 ]
-* [ 0 | 0 0 I ]
-*
-* [ C | -S 0 0 ]
-* [ U1 | ] [ 0 | 0 -I 0 ] [ V1 | ]**H
-* = [---------] [---------------] [---------] .
-* [ | U2 ] [ S | C 0 0 ] [ | V2 ]
-* [ 0 | 0 0 I ]
-*
-* X is M-by-M, its top-left block is P-by-Q, and Q must be no larger
-* than P, M-P, or M-Q. (If Q is not the smallest index, then X must be
-* transposed and/or permuted. This can be done in constant time using
-* the TRANS and SIGNS options. See CUNCSD for details.)
-*
-* The bidiagonal matrices B11, B12, B21, and B22 are represented
-* implicitly by angles THETA(1:Q) and PHI(1:Q-1).
-*
-* The unitary matrices U1, U2, V1T, and V2T are input/output.
-* The input matrices are pre- or post-multiplied by the appropriate
-* singular vector matrices.
-*
-* Arguments
-* =========
-*
-* JOBU1 (input) CHARACTER
-* = 'Y': U1 is updated;
-* otherwise: U1 is not updated.
-*
-* JOBU2 (input) CHARACTER
-* = 'Y': U2 is updated;
-* otherwise: U2 is not updated.
-*
-* JOBV1T (input) CHARACTER
-* = 'Y': V1T is updated;
-* otherwise: V1T is not updated.
-*
-* JOBV2T (input) CHARACTER
-* = 'Y': V2T is updated;
-* otherwise: V2T is not updated.
-*
-* TRANS (input) CHARACTER
-* = 'T': X, U1, U2, V1T, and V2T are stored in row-major
-* order;
-* otherwise: X, U1, U2, V1T, and V2T are stored in column-
-* major order.
-*
-* M (input) INTEGER
-* The number of rows and columns in X, the unitary matrix in
-* bidiagonal-block form.
-*
-* P (input) INTEGER
-* The number of rows in the top-left block of X. 0 <= P <= M.
-*
-* Q (input) INTEGER
-* The number of columns in the top-left block of X.
-* 0 <= Q <= MIN(P,M-P,M-Q).
-*
-* THETA (input/output) REAL array, dimension (Q)
-* On entry, the angles THETA(1),...,THETA(Q) that, along with
-* PHI(1), ...,PHI(Q-1), define the matrix in bidiagonal-block
-* form. On exit, the angles whose cosines and sines define the
-* diagonal blocks in the CS decomposition.
-*
-* PHI (input/workspace) REAL array, dimension (Q-1)
-* The angles PHI(1),...,PHI(Q-1) that, along with THETA(1),...,
-* THETA(Q), define the matrix in bidiagonal-block form.
-*
-* U1 (input/output) COMPLEX array, dimension (LDU1,P)
-* On entry, an LDU1-by-P matrix. On exit, U1 is postmultiplied
-* by the left singular vector matrix common to [ B11 ; 0 ] and
-* [ B12 0 0 ; 0 -I 0 0 ].
-*
-* LDU1 (input) INTEGER
-* The leading dimension of the array U1.
-*
-* U2 (input/output) COMPLEX array, dimension (LDU2,M-P)
-* On entry, an LDU2-by-(M-P) matrix. On exit, U2 is
-* postmultiplied by the left singular vector matrix common to
-* [ B21 ; 0 ] and [ B22 0 0 ; 0 0 I ].
-*
-* LDU2 (input) INTEGER
-* The leading dimension of the array U2.
-*
-* V1T (input/output) COMPLEX array, dimension (LDV1T,Q)
-* On entry, a LDV1T-by-Q matrix. On exit, V1T is premultiplied
-* by the conjugate transpose of the right singular vector
-* matrix common to [ B11 ; 0 ] and [ B21 ; 0 ].
-*
-* LDV1T (input) INTEGER
-* The leading dimension of the array V1T.
-*
-* V2T (input/output) COMPLEX array, dimenison (LDV2T,M-Q)
-* On entry, a LDV2T-by-(M-Q) matrix. On exit, V2T is
-* premultiplied by the conjugate transpose of the right
-* singular vector matrix common to [ B12 0 0 ; 0 -I 0 ] and
-* [ B22 0 0 ; 0 0 I ].
-*
-* LDV2T (input) INTEGER
-* The leading dimension of the array V2T.
-*
-* B11D (output) REAL array, dimension (Q)
-* When CBBCSD converges, B11D contains the cosines of THETA(1),
-* ..., THETA(Q). If CBBCSD fails to converge, then B11D
-* contains the diagonal of the partially reduced top-left
-* block.
-*
-* B11E (output) REAL array, dimension (Q-1)
-* When CBBCSD converges, B11E contains zeros. If CBBCSD fails
-* to converge, then B11E contains the superdiagonal of the
-* partially reduced top-left block.
-*
-* B12D (output) REAL array, dimension (Q)
-* When CBBCSD converges, B12D contains the negative sines of
-* THETA(1), ..., THETA(Q). If CBBCSD fails to converge, then
-* B12D contains the diagonal of the partially reduced top-right
-* block.
-*
-* B12E (output) REAL array, dimension (Q-1)
-* When CBBCSD converges, B12E contains zeros. If CBBCSD fails
-* to converge, then B12E contains the subdiagonal of the
-* partially reduced top-right block.
-*
-* RWORK (workspace) REAL array, dimension (MAX(1,LWORK))
-* On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
-*
-* LRWORK (input) INTEGER
-* The dimension of the array RWORK. LRWORK >= MAX(1,8*Q).
-*
-* If LRWORK = -1, then a workspace query is assumed; the
-* routine only calculates the optimal size of the RWORK array,
-* returns this value as the first entry of the work array, and
-* no error message related to LRWORK is issued by XERBLA.
-*
-* INFO (output) INTEGER
-* = 0: successful exit.
-* < 0: if INFO = -i, the i-th argument had an illegal value.
-* > 0: if CBBCSD did not converge, INFO specifies the number
-* of nonzero entries in PHI, and B11D, B11E, etc.,
-* contain the partially reduced matrix.
-*
-* Reference
-* =========
-*
-* [1] Brian D. Sutton. Computing the complete CS decomposition. Numer.
-* Algorithms, 50(1):33-65, 2009.
-*
-* Internal Parameters
-* ===================
-*
-* TOLMUL REAL, default = MAX(10,MIN(100,EPS**(-1/8)))
-* TOLMUL controls the convergence criterion of the QR loop.
-* Angles THETA(i), PHI(i) are rounded to 0 or PI/2 when they
-* are within TOLMUL*EPS of either bound.
-*
* ===================================================================
*
* .. Parameters ..