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author | julie <julielangou@users.noreply.github.com> | 2012-07-27 06:42:44 +0000 |
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committer | julie <julielangou@users.noreply.github.com> | 2012-07-27 06:42:44 +0000 |
commit | 199c646448f65fb375a8aaf7383c705dab58f550 (patch) | |
tree | 5681fbfbb7d700a8a1da347fa25f90a2967c14a2 /SRC/cunbdb6.f | |
parent | 2a180a73cd84e5bfdd306d649e1713e144a6f132 (diff) | |
download | lapack-199c646448f65fb375a8aaf7383c705dab58f550.tar.gz lapack-199c646448f65fb375a8aaf7383c705dab58f550.tar.bz2 lapack-199c646448f65fb375a8aaf7383c705dab58f550.zip |
Commit Brian Sutton new CS Decomposition routines.
All the routines from the SRC folder have been updated to integrate the current Doxygen layout.
Everything seems to be fine, all tests passed without problem.
Diffstat (limited to 'SRC/cunbdb6.f')
-rw-r--r-- | SRC/cunbdb6.f | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/SRC/cunbdb6.f b/SRC/cunbdb6.f new file mode 100644 index 00000000..943e5224 --- /dev/null +++ b/SRC/cunbdb6.f @@ -0,0 +1,313 @@ +*> \brief \b CUNBDB6 +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download CUNBDB6 + dependencies +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/cunbdb6.f"> +*> [TGZ]</a> +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/cunbdb6.f"> +*> [ZIP]</a> +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/cunbdb6.f"> +*> [TXT]</a> +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE CUNBDB6( M1, M2, N, X1, INCX1, X2, INCX2, Q1, LDQ1, Q2, +* LDQ2, WORK, LWORK, INFO ) +* +* .. Scalar Arguments .. +* INTEGER INCX1, INCX2, INFO, LDQ1, LDQ2, LWORK, M1, M2, +* $ N +* .. +* .. Array Arguments .. +* COMPLEX Q1(LDQ1,*), Q2(LDQ2,*), WORK(*), X1(*), X2(*) +* .. +* +* +*> \par Purpose: +*> ============= +*> +*>\verbatim +*> +*> CUNBDB6 orthogonalizes the column vector +*> X = [ X1 ] +*> [ X2 ] +*> with respect to the columns of +*> Q = [ Q1 ] . +*> [ Q2 ] +*> The columns of Q must be orthonormal. +*> +*> If the projection is zero according to Kahan's "twice is enough" +*> criterion, then the zero vector is returned. +*> +*>\endverbatim +* +* Arguments: +* ========== +* +*> \param[in] M1 +*> \verbatim +*> M1 is INTEGER +*> The dimension of X1 and the number of rows in Q1. 0 <= M1. +*> \endverbatim +*> +*> \param[in] M2 +*> \verbatim +*> M2 is INTEGER +*> The dimension of X2 and the number of rows in Q2. 0 <= M2. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The number of columns in Q1 and Q2. 0 <= N. +*> \endverbatim +*> +*> \param[in,out] X1 +*> \verbatim +*> X1 is COMPLEX array, dimension (M1) +*> On entry, the top part of the vector to be orthogonalized. +*> On exit, the top part of the projected vector. +*> \endverbatim +*> +*> \param[in] INCX1 +*> \verbatim +*> INCX1 is INTEGER +*> Increment for entries of X1. +*> \endverbatim +*> +*> \param[in,out] X2 +*> \verbatim +*> X2 is COMPLEX array, dimension (M2) +*> On entry, the bottom part of the vector to be +*> orthogonalized. On exit, the bottom part of the projected +*> vector. +*> \endverbatim +*> +*> \param[in] INCX2 +*> \verbatim +*> INCX2 is INTEGER +*> Increment for entries of X2. +*> \endverbatim +*> +*> \param[in] Q1 +*> \verbatim +*> Q1 is COMPLEX array, dimension (LDQ1, N) +*> The top part of the orthonormal basis matrix. +*> \endverbatim +*> +*> \param[in] LDQ1 +*> \verbatim +*> LDQ1 is INTEGER +*> The leading dimension of Q1. LDQ1 >= M1. +*> \endverbatim +*> +*> \param[in] Q2 +*> \verbatim +*> Q2 is COMPLEX array, dimension (LDQ2, N) +*> The bottom part of the orthonormal basis matrix. +*> \endverbatim +*> +*> \param[in] LDQ2 +*> \verbatim +*> LDQ2 is INTEGER +*> The leading dimension of Q2. LDQ2 >= M2. +*> \endverbatim +*> +*> \param[out] WORK +*> \verbatim +*> WORK is COMPLEX array, dimension (LWORK) +*> \endverbatim +*> +*> \param[in] LWORK +*> \verbatim +*> LWORK is INTEGER +*> The dimension of the array WORK. LWORK >= N. +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit. +*> < 0: if INFO = -i, the i-th argument had an illegal value. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date July 2012 +* +*> \ingroup complexOTHERcomputational +* +* ===================================================================== + SUBROUTINE CUNBDB6( M1, M2, N, X1, INCX1, X2, INCX2, Q1, LDQ1, Q2, + $ LDQ2, WORK, LWORK, INFO ) +* +* -- LAPACK computational routine (version 3.5.0) -- +* -- LAPACK is a software package provided by Univ. of Tennessee, -- +* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- +* July 2012 +* +* .. Scalar Arguments .. + INTEGER INCX1, INCX2, INFO, LDQ1, LDQ2, LWORK, M1, M2, + $ N +* .. +* .. Array Arguments .. + COMPLEX Q1(LDQ1,*), Q2(LDQ2,*), WORK(*), X1(*), X2(*) +* .. +* +* ===================================================================== +* +* .. Parameters .. + REAL ALPHASQ, REALONE, REALZERO + PARAMETER ( ALPHASQ = 0.01E0, REALONE = 1.0E0, + $ REALZERO = 0.0E0 ) + COMPLEX NEGONE, ONE, ZERO + PARAMETER ( NEGONE = (-1.0E0,0.0E0), ONE = (1.0E0,0.0E0), + $ ZERO = (0.0E0,0.0E0) ) +* .. +* .. Local Scalars .. + INTEGER I + REAL NORMSQ1, NORMSQ2, SCL1, SCL2, SSQ1, SSQ2 +* .. +* .. External Subroutines .. + EXTERNAL CGEMV, CLASSQ, XERBLA +* .. +* .. Intrinsic Function .. + INTRINSIC MAX +* .. +* .. Executable Statements .. +* +* Test input arguments +* + INFO = 0 + IF( M1 .LT. 0 ) THEN + INFO = -1 + ELSE IF( M2 .LT. 0 ) THEN + INFO = -2 + ELSE IF( N .LT. 0 ) THEN + INFO = -3 + ELSE IF( INCX1 .LT. 1 ) THEN + INFO = -5 + ELSE IF( INCX2 .LT. 1 ) THEN + INFO = -7 + ELSE IF( LDQ1 .LT. MAX( 1, M1 ) ) THEN + INFO = -9 + ELSE IF( LDQ2 .LT. MAX( 1, M2 ) ) THEN + INFO = -11 + ELSE IF( LWORK .LT. N ) THEN + INFO = -13 + END IF +* + IF( INFO .NE. 0 ) THEN + CALL XERBLA( 'CUNBDB6', -INFO ) + RETURN + END IF +* +* First, project X onto the orthogonal complement of Q's column +* space +* + SCL1 = REALZERO + SSQ1 = REALONE + CALL CLASSQ( M1, X1, INCX1, SCL1, SSQ1 ) + SCL2 = REALZERO + SSQ2 = REALONE + CALL CLASSQ( M2, X2, INCX2, SCL2, SSQ2 ) + NORMSQ1 = SCL1**2*SSQ1 + SCL2**2*SSQ2 +* + IF( M1 .EQ. 0 ) THEN + DO I = 1, N + WORK(I) = ZERO + END DO + ELSE + CALL CGEMV( 'C', M1, N, ONE, Q1, LDQ1, X1, INCX1, ZERO, WORK, + $ 1 ) + END IF +* + CALL CGEMV( 'C', M2, N, ONE, Q2, LDQ2, X2, INCX2, ONE, WORK, 1 ) +* + CALL CGEMV( 'N', M1, N, NEGONE, Q1, LDQ1, WORK, 1, ONE, X1, + $ INCX1 ) + CALL CGEMV( 'N', M2, N, NEGONE, Q2, LDQ2, WORK, 1, ONE, X2, + $ INCX2 ) +* + SCL1 = REALZERO + SSQ1 = REALONE + CALL CLASSQ( M1, X1, INCX1, SCL1, SSQ1 ) + SCL2 = REALZERO + SSQ2 = REALONE + CALL CLASSQ( M2, X2, INCX2, SCL2, SSQ2 ) + NORMSQ2 = SCL1**2*SSQ1 + SCL2**2*SSQ2 +* +* If projection is sufficiently large in norm, then stop. +* If projection is zero, then stop. +* Otherwise, project again. +* + IF( NORMSQ2 .GE. ALPHASQ*NORMSQ1 ) THEN + RETURN + END IF +* + IF( NORMSQ2 .EQ. ZERO ) THEN + RETURN + END IF +* + NORMSQ1 = NORMSQ2 +* + DO I = 1, N + WORK(I) = ZERO + END DO +* + IF( M1 .EQ. 0 ) THEN + DO I = 1, N + WORK(I) = ZERO + END DO + ELSE + CALL CGEMV( 'C', M1, N, ONE, Q1, LDQ1, X1, INCX1, ZERO, WORK, + $ 1 ) + END IF +* + CALL CGEMV( 'C', M2, N, ONE, Q2, LDQ2, X2, INCX2, ONE, WORK, 1 ) +* + CALL CGEMV( 'N', M1, N, NEGONE, Q1, LDQ1, WORK, 1, ONE, X1, + $ INCX1 ) + CALL CGEMV( 'N', M2, N, NEGONE, Q2, LDQ2, WORK, 1, ONE, X2, + $ INCX2 ) +* + SCL1 = REALZERO + SSQ1 = REALONE + CALL CLASSQ( M1, X1, INCX1, SCL1, SSQ1 ) + SCL2 = REALZERO + SSQ2 = REALONE + CALL CLASSQ( M1, X1, INCX1, SCL1, SSQ1 ) + NORMSQ2 = SCL1**2*SSQ1 + SCL2**2*SSQ2 +* +* If second projection is sufficiently large in norm, then do +* nothing more. Alternatively, if it shrunk significantly, then +* truncate it to zero. +* + IF( NORMSQ2 .LT. ALPHASQ*NORMSQ1 ) THEN + DO I = 1, M1 + X1(I) = ZERO + END DO + DO I = 1, M2 + X2(I) = ZERO + END DO + END IF +* + RETURN +* +* End of CUNBDB6 +* + END + |