removed lapack 3.6.0
This commit is contained in:
@@ -1,630 +0,0 @@
|
||||
*> \brief \b ZTREVC3
|
||||
*
|
||||
* =========== DOCUMENTATION ===========
|
||||
*
|
||||
* Online html documentation available at
|
||||
* http://www.netlib.org/lapack/explore-html/
|
||||
*
|
||||
*> \htmlonly
|
||||
*> Download ZTREVC3 + dependencies
|
||||
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ztrevc3.f">
|
||||
*> [TGZ]</a>
|
||||
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ztrevc3.f">
|
||||
*> [ZIP]</a>
|
||||
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ztrevc3.f">
|
||||
*> [TXT]</a>
|
||||
*> \endhtmlonly
|
||||
*
|
||||
* Definition:
|
||||
* ===========
|
||||
*
|
||||
* SUBROUTINE ZTREVC3( SIDE, HOWMNY, SELECT, N, T, LDT, VL, LDVL,
|
||||
* VR, LDVR, MM, M, WORK, LWORK, RWORK, INFO )
|
||||
*
|
||||
* .. Scalar Arguments ..
|
||||
* CHARACTER HOWMNY, SIDE
|
||||
* INTEGER INFO, LDT, LDVL, LDVR, LWORK, M, MM, N
|
||||
* ..
|
||||
* .. Array Arguments ..
|
||||
* LOGICAL SELECT( * )
|
||||
* DOUBLE PRECISION RWORK( * )
|
||||
* COMPLEX*16 T( LDT, * ), VL( LDVL, * ), VR( LDVR, * ),
|
||||
* $ WORK( * )
|
||||
* ..
|
||||
*
|
||||
*
|
||||
*> \par Purpose:
|
||||
* =============
|
||||
*>
|
||||
*> \verbatim
|
||||
*>
|
||||
*> ZTREVC3 computes some or all of the right and/or left eigenvectors of
|
||||
*> a complex upper triangular matrix T.
|
||||
*> Matrices of this type are produced by the Schur factorization of
|
||||
*> a complex general matrix: A = Q*T*Q**H, as computed by ZHSEQR.
|
||||
*>
|
||||
*> The right eigenvector x and the left eigenvector y of T corresponding
|
||||
*> to an eigenvalue w are defined by:
|
||||
*>
|
||||
*> T*x = w*x, (y**H)*T = w*(y**H)
|
||||
*>
|
||||
*> where y**H denotes the conjugate transpose of the vector y.
|
||||
*> The eigenvalues are not input to this routine, but are read directly
|
||||
*> from the diagonal of T.
|
||||
*>
|
||||
*> This routine returns the matrices X and/or Y of right and left
|
||||
*> eigenvectors of T, or the products Q*X and/or Q*Y, where Q is an
|
||||
*> input matrix. If Q is the unitary factor that reduces a matrix A to
|
||||
*> Schur form T, then Q*X and Q*Y are the matrices of right and left
|
||||
*> eigenvectors of A.
|
||||
*>
|
||||
*> This uses a Level 3 BLAS version of the back transformation.
|
||||
*> \endverbatim
|
||||
*
|
||||
* Arguments:
|
||||
* ==========
|
||||
*
|
||||
*> \param[in] SIDE
|
||||
*> \verbatim
|
||||
*> SIDE is CHARACTER*1
|
||||
*> = 'R': compute right eigenvectors only;
|
||||
*> = 'L': compute left eigenvectors only;
|
||||
*> = 'B': compute both right and left eigenvectors.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] HOWMNY
|
||||
*> \verbatim
|
||||
*> HOWMNY is CHARACTER*1
|
||||
*> = 'A': compute all right and/or left eigenvectors;
|
||||
*> = 'B': compute all right and/or left eigenvectors,
|
||||
*> backtransformed using the matrices supplied in
|
||||
*> VR and/or VL;
|
||||
*> = 'S': compute selected right and/or left eigenvectors,
|
||||
*> as indicated by the logical array SELECT.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] SELECT
|
||||
*> \verbatim
|
||||
*> SELECT is LOGICAL array, dimension (N)
|
||||
*> If HOWMNY = 'S', SELECT specifies the eigenvectors to be
|
||||
*> computed.
|
||||
*> The eigenvector corresponding to the j-th eigenvalue is
|
||||
*> computed if SELECT(j) = .TRUE..
|
||||
*> Not referenced if HOWMNY = 'A' or 'B'.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] N
|
||||
*> \verbatim
|
||||
*> N is INTEGER
|
||||
*> The order of the matrix T. N >= 0.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in,out] T
|
||||
*> \verbatim
|
||||
*> T is COMPLEX*16 array, dimension (LDT,N)
|
||||
*> The upper triangular matrix T. T is modified, but restored
|
||||
*> on exit.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] LDT
|
||||
*> \verbatim
|
||||
*> LDT is INTEGER
|
||||
*> The leading dimension of the array T. LDT >= max(1,N).
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in,out] VL
|
||||
*> \verbatim
|
||||
*> VL is COMPLEX*16 array, dimension (LDVL,MM)
|
||||
*> On entry, if SIDE = 'L' or 'B' and HOWMNY = 'B', VL must
|
||||
*> contain an N-by-N matrix Q (usually the unitary matrix Q of
|
||||
*> Schur vectors returned by ZHSEQR).
|
||||
*> On exit, if SIDE = 'L' or 'B', VL contains:
|
||||
*> if HOWMNY = 'A', the matrix Y of left eigenvectors of T;
|
||||
*> if HOWMNY = 'B', the matrix Q*Y;
|
||||
*> if HOWMNY = 'S', the left eigenvectors of T specified by
|
||||
*> SELECT, stored consecutively in the columns
|
||||
*> of VL, in the same order as their
|
||||
*> eigenvalues.
|
||||
*> Not referenced if SIDE = 'R'.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] LDVL
|
||||
*> \verbatim
|
||||
*> LDVL is INTEGER
|
||||
*> The leading dimension of the array VL.
|
||||
*> LDVL >= 1, and if SIDE = 'L' or 'B', LDVL >= N.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in,out] VR
|
||||
*> \verbatim
|
||||
*> VR is COMPLEX*16 array, dimension (LDVR,MM)
|
||||
*> On entry, if SIDE = 'R' or 'B' and HOWMNY = 'B', VR must
|
||||
*> contain an N-by-N matrix Q (usually the unitary matrix Q of
|
||||
*> Schur vectors returned by ZHSEQR).
|
||||
*> On exit, if SIDE = 'R' or 'B', VR contains:
|
||||
*> if HOWMNY = 'A', the matrix X of right eigenvectors of T;
|
||||
*> if HOWMNY = 'B', the matrix Q*X;
|
||||
*> if HOWMNY = 'S', the right eigenvectors of T specified by
|
||||
*> SELECT, stored consecutively in the columns
|
||||
*> of VR, in the same order as their
|
||||
*> eigenvalues.
|
||||
*> Not referenced if SIDE = 'L'.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] LDVR
|
||||
*> \verbatim
|
||||
*> LDVR is INTEGER
|
||||
*> The leading dimension of the array VR.
|
||||
*> LDVR >= 1, and if SIDE = 'R' or 'B', LDVR >= N.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] MM
|
||||
*> \verbatim
|
||||
*> MM is INTEGER
|
||||
*> The number of columns in the arrays VL and/or VR. MM >= M.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[out] M
|
||||
*> \verbatim
|
||||
*> M is INTEGER
|
||||
*> The number of columns in the arrays VL and/or VR actually
|
||||
*> used to store the eigenvectors.
|
||||
*> If HOWMNY = 'A' or 'B', M is set to N.
|
||||
*> Each selected eigenvector occupies one column.
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[out] WORK
|
||||
*> \verbatim
|
||||
*> WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] LWORK
|
||||
*> \verbatim
|
||||
*> LWORK is INTEGER
|
||||
*> The dimension of array WORK. LWORK >= max(1,2*N).
|
||||
*> For optimum performance, LWORK >= N + 2*N*NB, where NB is
|
||||
*> the optimal blocksize.
|
||||
*>
|
||||
*> 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
|
||||
*>
|
||||
*> \param[out] RWORK
|
||||
*> \verbatim
|
||||
*> RWORK is DOUBLE PRECISION array, dimension (LRWORK)
|
||||
*> \endverbatim
|
||||
*>
|
||||
*> \param[in] LRWORK
|
||||
*> \verbatim
|
||||
*> LRWORK is INTEGER
|
||||
*> The dimension of array RWORK. LRWORK >= max(1,N).
|
||||
*>
|
||||
*> 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 RWORK 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
|
||||
*> \endverbatim
|
||||
*
|
||||
* Authors:
|
||||
* ========
|
||||
*
|
||||
*> \author Univ. of Tennessee
|
||||
*> \author Univ. of California Berkeley
|
||||
*> \author Univ. of Colorado Denver
|
||||
*> \author NAG Ltd.
|
||||
*
|
||||
*> \date November 2011
|
||||
*
|
||||
* @precisions fortran z -> c
|
||||
*
|
||||
*> \ingroup complex16OTHERcomputational
|
||||
*
|
||||
*> \par Further Details:
|
||||
* =====================
|
||||
*>
|
||||
*> \verbatim
|
||||
*>
|
||||
*> The algorithm used in this program is basically backward (forward)
|
||||
*> substitution, with scaling to make the the code robust against
|
||||
*> possible overflow.
|
||||
*>
|
||||
*> Each eigenvector is normalized so that the element of largest
|
||||
*> magnitude has magnitude 1; here the magnitude of a complex number
|
||||
*> (x,y) is taken to be |x| + |y|.
|
||||
*> \endverbatim
|
||||
*>
|
||||
* =====================================================================
|
||||
SUBROUTINE ZTREVC3( SIDE, HOWMNY, SELECT, N, T, LDT, VL, LDVL, VR,
|
||||
$ LDVR, MM, M, WORK, LWORK, RWORK, LRWORK, INFO)
|
||||
IMPLICIT NONE
|
||||
*
|
||||
* -- LAPACK computational 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..--
|
||||
* November 2011
|
||||
*
|
||||
* .. Scalar Arguments ..
|
||||
CHARACTER HOWMNY, SIDE
|
||||
INTEGER INFO, LDT, LDVL, LDVR, LWORK, LRWORK, M, MM, N
|
||||
* ..
|
||||
* .. Array Arguments ..
|
||||
LOGICAL SELECT( * )
|
||||
DOUBLE PRECISION RWORK( * )
|
||||
COMPLEX*16 T( LDT, * ), VL( LDVL, * ), VR( LDVR, * ),
|
||||
$ WORK( * )
|
||||
* ..
|
||||
*
|
||||
* =====================================================================
|
||||
*
|
||||
* .. Parameters ..
|
||||
DOUBLE PRECISION ZERO, ONE
|
||||
PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 )
|
||||
COMPLEX*16 CZERO, CONE
|
||||
PARAMETER ( CZERO = ( 0.0D+0, 0.0D+0 ),
|
||||
$ CONE = ( 1.0D+0, 0.0D+0 ) )
|
||||
INTEGER NBMIN, NBMAX
|
||||
PARAMETER ( NBMIN = 8, NBMAX = 128 )
|
||||
* ..
|
||||
* .. Local Scalars ..
|
||||
LOGICAL ALLV, BOTHV, LEFTV, LQUERY, OVER, RIGHTV, SOMEV
|
||||
INTEGER I, II, IS, J, K, KI, IV, MAXWRK, NB
|
||||
DOUBLE PRECISION OVFL, REMAX, SCALE, SMIN, SMLNUM, ULP, UNFL
|
||||
COMPLEX*16 CDUM
|
||||
* ..
|
||||
* .. External Functions ..
|
||||
LOGICAL LSAME
|
||||
INTEGER ILAENV, IZAMAX
|
||||
DOUBLE PRECISION DLAMCH, DZASUM
|
||||
EXTERNAL LSAME, ILAENV, IZAMAX, DLAMCH, DZASUM
|
||||
* ..
|
||||
* .. External Subroutines ..
|
||||
EXTERNAL XERBLA, ZCOPY, ZDSCAL, ZGEMV, ZLATRS
|
||||
* ..
|
||||
* .. Intrinsic Functions ..
|
||||
INTRINSIC ABS, DBLE, DCMPLX, CONJG, AIMAG, MAX
|
||||
* ..
|
||||
* .. Statement Functions ..
|
||||
DOUBLE PRECISION CABS1
|
||||
* ..
|
||||
* .. Statement Function definitions ..
|
||||
CABS1( CDUM ) = ABS( DBLE( CDUM ) ) + ABS( AIMAG( CDUM ) )
|
||||
* ..
|
||||
* .. Executable Statements ..
|
||||
*
|
||||
* Decode and test the input parameters
|
||||
*
|
||||
BOTHV = LSAME( SIDE, 'B' )
|
||||
RIGHTV = LSAME( SIDE, 'R' ) .OR. BOTHV
|
||||
LEFTV = LSAME( SIDE, 'L' ) .OR. BOTHV
|
||||
*
|
||||
ALLV = LSAME( HOWMNY, 'A' )
|
||||
OVER = LSAME( HOWMNY, 'B' )
|
||||
SOMEV = LSAME( HOWMNY, 'S' )
|
||||
*
|
||||
* Set M to the number of columns required to store the selected
|
||||
* eigenvectors.
|
||||
*
|
||||
IF( SOMEV ) THEN
|
||||
M = 0
|
||||
DO 10 J = 1, N
|
||||
IF( SELECT( J ) )
|
||||
$ M = M + 1
|
||||
10 CONTINUE
|
||||
ELSE
|
||||
M = N
|
||||
END IF
|
||||
*
|
||||
INFO = 0
|
||||
NB = ILAENV( 1, 'ZTREVC', SIDE // HOWMNY, N, -1, -1, -1 )
|
||||
MAXWRK = N + 2*N*NB
|
||||
WORK(1) = MAXWRK
|
||||
RWORK(1) = N
|
||||
LQUERY = ( LWORK.EQ.-1 .OR. LRWORK.EQ.-1 )
|
||||
IF( .NOT.RIGHTV .AND. .NOT.LEFTV ) THEN
|
||||
INFO = -1
|
||||
ELSE IF( .NOT.ALLV .AND. .NOT.OVER .AND. .NOT.SOMEV ) THEN
|
||||
INFO = -2
|
||||
ELSE IF( N.LT.0 ) THEN
|
||||
INFO = -4
|
||||
ELSE IF( LDT.LT.MAX( 1, N ) ) THEN
|
||||
INFO = -6
|
||||
ELSE IF( LDVL.LT.1 .OR. ( LEFTV .AND. LDVL.LT.N ) ) THEN
|
||||
INFO = -8
|
||||
ELSE IF( LDVR.LT.1 .OR. ( RIGHTV .AND. LDVR.LT.N ) ) THEN
|
||||
INFO = -10
|
||||
ELSE IF( MM.LT.M ) THEN
|
||||
INFO = -11
|
||||
ELSE IF( LWORK.LT.MAX( 1, 2*N ) .AND. .NOT.LQUERY ) THEN
|
||||
INFO = -14
|
||||
ELSE IF ( LRWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
|
||||
INFO = -16
|
||||
END IF
|
||||
IF( INFO.NE.0 ) THEN
|
||||
CALL XERBLA( 'ZTREVC3', -INFO )
|
||||
RETURN
|
||||
ELSE IF( LQUERY ) THEN
|
||||
RETURN
|
||||
END IF
|
||||
*
|
||||
* Quick return if possible.
|
||||
*
|
||||
IF( N.EQ.0 )
|
||||
$ RETURN
|
||||
*
|
||||
* Use blocked version of back-transformation if sufficient workspace.
|
||||
* Zero-out the workspace to avoid potential NaN propagation.
|
||||
*
|
||||
IF( OVER .AND. LWORK .GE. N + 2*N*NBMIN ) THEN
|
||||
NB = (LWORK - N) / (2*N)
|
||||
NB = MIN( NB, NBMAX )
|
||||
CALL ZLASET( 'F', N, 1+2*NB, CZERO, CZERO, WORK, N )
|
||||
ELSE
|
||||
NB = 1
|
||||
END IF
|
||||
*
|
||||
* Set the constants to control overflow.
|
||||
*
|
||||
UNFL = DLAMCH( 'Safe minimum' )
|
||||
OVFL = ONE / UNFL
|
||||
CALL DLABAD( UNFL, OVFL )
|
||||
ULP = DLAMCH( 'Precision' )
|
||||
SMLNUM = UNFL*( N / ULP )
|
||||
*
|
||||
* Store the diagonal elements of T in working array WORK.
|
||||
*
|
||||
DO 20 I = 1, N
|
||||
WORK( I ) = T( I, I )
|
||||
20 CONTINUE
|
||||
*
|
||||
* Compute 1-norm of each column of strictly upper triangular
|
||||
* part of T to control overflow in triangular solver.
|
||||
*
|
||||
RWORK( 1 ) = ZERO
|
||||
DO 30 J = 2, N
|
||||
RWORK( J ) = DZASUM( J-1, T( 1, J ), 1 )
|
||||
30 CONTINUE
|
||||
*
|
||||
IF( RIGHTV ) THEN
|
||||
*
|
||||
* ============================================================
|
||||
* Compute right eigenvectors.
|
||||
*
|
||||
* IV is index of column in current block.
|
||||
* Non-blocked version always uses IV=NB=1;
|
||||
* blocked version starts with IV=NB, goes down to 1.
|
||||
* (Note the "0-th" column is used to store the original diagonal.)
|
||||
IV = NB
|
||||
IS = M
|
||||
DO 80 KI = N, 1, -1
|
||||
IF( SOMEV ) THEN
|
||||
IF( .NOT.SELECT( KI ) )
|
||||
$ GO TO 80
|
||||
END IF
|
||||
SMIN = MAX( ULP*( CABS1( T( KI, KI ) ) ), SMLNUM )
|
||||
*
|
||||
* --------------------------------------------------------
|
||||
* Complex right eigenvector
|
||||
*
|
||||
WORK( KI + IV*N ) = CONE
|
||||
*
|
||||
* Form right-hand side.
|
||||
*
|
||||
DO 40 K = 1, KI - 1
|
||||
WORK( K + IV*N ) = -T( K, KI )
|
||||
40 CONTINUE
|
||||
*
|
||||
* Solve upper triangular system:
|
||||
* [ T(1:KI-1,1:KI-1) - T(KI,KI) ]*X = SCALE*WORK.
|
||||
*
|
||||
DO 50 K = 1, KI - 1
|
||||
T( K, K ) = T( K, K ) - T( KI, KI )
|
||||
IF( CABS1( T( K, K ) ).LT.SMIN )
|
||||
$ T( K, K ) = SMIN
|
||||
50 CONTINUE
|
||||
*
|
||||
IF( KI.GT.1 ) THEN
|
||||
CALL ZLATRS( 'Upper', 'No transpose', 'Non-unit', 'Y',
|
||||
$ KI-1, T, LDT, WORK( 1 + IV*N ), SCALE,
|
||||
$ RWORK, INFO )
|
||||
WORK( KI + IV*N ) = SCALE
|
||||
END IF
|
||||
*
|
||||
* Copy the vector x or Q*x to VR and normalize.
|
||||
*
|
||||
IF( .NOT.OVER ) THEN
|
||||
* ------------------------------
|
||||
* no back-transform: copy x to VR and normalize.
|
||||
CALL ZCOPY( KI, WORK( 1 + IV*N ), 1, VR( 1, IS ), 1 )
|
||||
*
|
||||
II = IZAMAX( KI, VR( 1, IS ), 1 )
|
||||
REMAX = ONE / CABS1( VR( II, IS ) )
|
||||
CALL ZDSCAL( KI, REMAX, VR( 1, IS ), 1 )
|
||||
*
|
||||
DO 60 K = KI + 1, N
|
||||
VR( K, IS ) = CZERO
|
||||
60 CONTINUE
|
||||
*
|
||||
ELSE IF( NB.EQ.1 ) THEN
|
||||
* ------------------------------
|
||||
* version 1: back-transform each vector with GEMV, Q*x.
|
||||
IF( KI.GT.1 )
|
||||
$ CALL ZGEMV( 'N', N, KI-1, CONE, VR, LDVR,
|
||||
$ WORK( 1 + IV*N ), 1, DCMPLX( SCALE ),
|
||||
$ VR( 1, KI ), 1 )
|
||||
*
|
||||
II = IZAMAX( N, VR( 1, KI ), 1 )
|
||||
REMAX = ONE / CABS1( VR( II, KI ) )
|
||||
CALL ZDSCAL( N, REMAX, VR( 1, KI ), 1 )
|
||||
*
|
||||
ELSE
|
||||
* ------------------------------
|
||||
* version 2: back-transform block of vectors with GEMM
|
||||
* zero out below vector
|
||||
DO K = KI + 1, N
|
||||
WORK( K + IV*N ) = CZERO
|
||||
END DO
|
||||
*
|
||||
* Columns IV:NB of work are valid vectors.
|
||||
* When the number of vectors stored reaches NB,
|
||||
* or if this was last vector, do the GEMM
|
||||
IF( (IV.EQ.1) .OR. (KI.EQ.1) ) THEN
|
||||
CALL ZGEMM( 'N', 'N', N, NB-IV+1, KI+NB-IV, CONE,
|
||||
$ VR, LDVR,
|
||||
$ WORK( 1 + (IV)*N ), N,
|
||||
$ CZERO,
|
||||
$ WORK( 1 + (NB+IV)*N ), N )
|
||||
* normalize vectors
|
||||
DO K = IV, NB
|
||||
II = IZAMAX( N, WORK( 1 + (NB+K)*N ), 1 )
|
||||
REMAX = ONE / CABS1( WORK( II + (NB+K)*N ) )
|
||||
CALL ZDSCAL( N, REMAX, WORK( 1 + (NB+K)*N ), 1 )
|
||||
END DO
|
||||
CALL ZLACPY( 'F', N, NB-IV+1,
|
||||
$ WORK( 1 + (NB+IV)*N ), N,
|
||||
$ VR( 1, KI ), LDVR )
|
||||
IV = NB
|
||||
ELSE
|
||||
IV = IV - 1
|
||||
END IF
|
||||
END IF
|
||||
*
|
||||
* Restore the original diagonal elements of T.
|
||||
*
|
||||
DO 70 K = 1, KI - 1
|
||||
T( K, K ) = WORK( K )
|
||||
70 CONTINUE
|
||||
*
|
||||
IS = IS - 1
|
||||
80 CONTINUE
|
||||
END IF
|
||||
*
|
||||
IF( LEFTV ) THEN
|
||||
*
|
||||
* ============================================================
|
||||
* Compute left eigenvectors.
|
||||
*
|
||||
* IV is index of column in current block.
|
||||
* Non-blocked version always uses IV=1;
|
||||
* blocked version starts with IV=1, goes up to NB.
|
||||
* (Note the "0-th" column is used to store the original diagonal.)
|
||||
IV = 1
|
||||
IS = 1
|
||||
DO 130 KI = 1, N
|
||||
*
|
||||
IF( SOMEV ) THEN
|
||||
IF( .NOT.SELECT( KI ) )
|
||||
$ GO TO 130
|
||||
END IF
|
||||
SMIN = MAX( ULP*( CABS1( T( KI, KI ) ) ), SMLNUM )
|
||||
*
|
||||
* --------------------------------------------------------
|
||||
* Complex left eigenvector
|
||||
*
|
||||
WORK( KI + IV*N ) = CONE
|
||||
*
|
||||
* Form right-hand side.
|
||||
*
|
||||
DO 90 K = KI + 1, N
|
||||
WORK( K + IV*N ) = -CONJG( T( KI, K ) )
|
||||
90 CONTINUE
|
||||
*
|
||||
* Solve conjugate-transposed triangular system:
|
||||
* [ T(KI+1:N,KI+1:N) - T(KI,KI) ]**H * X = SCALE*WORK.
|
||||
*
|
||||
DO 100 K = KI + 1, N
|
||||
T( K, K ) = T( K, K ) - T( KI, KI )
|
||||
IF( CABS1( T( K, K ) ).LT.SMIN )
|
||||
$ T( K, K ) = SMIN
|
||||
100 CONTINUE
|
||||
*
|
||||
IF( KI.LT.N ) THEN
|
||||
CALL ZLATRS( 'Upper', 'Conjugate transpose', 'Non-unit',
|
||||
$ 'Y', N-KI, T( KI+1, KI+1 ), LDT,
|
||||
$ WORK( KI+1 + IV*N ), SCALE, RWORK, INFO )
|
||||
WORK( KI + IV*N ) = SCALE
|
||||
END IF
|
||||
*
|
||||
* Copy the vector x or Q*x to VL and normalize.
|
||||
*
|
||||
IF( .NOT.OVER ) THEN
|
||||
* ------------------------------
|
||||
* no back-transform: copy x to VL and normalize.
|
||||
CALL ZCOPY( N-KI+1, WORK( KI + IV*N ), 1, VL(KI,IS), 1 )
|
||||
*
|
||||
II = IZAMAX( N-KI+1, VL( KI, IS ), 1 ) + KI - 1
|
||||
REMAX = ONE / CABS1( VL( II, IS ) )
|
||||
CALL ZDSCAL( N-KI+1, REMAX, VL( KI, IS ), 1 )
|
||||
*
|
||||
DO 110 K = 1, KI - 1
|
||||
VL( K, IS ) = CZERO
|
||||
110 CONTINUE
|
||||
*
|
||||
ELSE IF( NB.EQ.1 ) THEN
|
||||
* ------------------------------
|
||||
* version 1: back-transform each vector with GEMV, Q*x.
|
||||
IF( KI.LT.N )
|
||||
$ CALL ZGEMV( 'N', N, N-KI, CONE, VL( 1, KI+1 ), LDVL,
|
||||
$ WORK( KI+1 + IV*N ), 1, DCMPLX( SCALE ),
|
||||
$ VL( 1, KI ), 1 )
|
||||
*
|
||||
II = IZAMAX( N, VL( 1, KI ), 1 )
|
||||
REMAX = ONE / CABS1( VL( II, KI ) )
|
||||
CALL ZDSCAL( N, REMAX, VL( 1, KI ), 1 )
|
||||
*
|
||||
ELSE
|
||||
* ------------------------------
|
||||
* version 2: back-transform block of vectors with GEMM
|
||||
* zero out above vector
|
||||
* could go from KI-NV+1 to KI-1
|
||||
DO K = 1, KI - 1
|
||||
WORK( K + IV*N ) = CZERO
|
||||
END DO
|
||||
*
|
||||
* Columns 1:IV of work are valid vectors.
|
||||
* When the number of vectors stored reaches NB,
|
||||
* or if this was last vector, do the GEMM
|
||||
IF( (IV.EQ.NB) .OR. (KI.EQ.N) ) THEN
|
||||
CALL ZGEMM( 'N', 'N', N, IV, N-KI+IV, ONE,
|
||||
$ VL( 1, KI-IV+1 ), LDVL,
|
||||
$ WORK( KI-IV+1 + (1)*N ), N,
|
||||
$ CZERO,
|
||||
$ WORK( 1 + (NB+1)*N ), N )
|
||||
* normalize vectors
|
||||
DO K = 1, IV
|
||||
II = IZAMAX( N, WORK( 1 + (NB+K)*N ), 1 )
|
||||
REMAX = ONE / CABS1( WORK( II + (NB+K)*N ) )
|
||||
CALL ZDSCAL( N, REMAX, WORK( 1 + (NB+K)*N ), 1 )
|
||||
END DO
|
||||
CALL ZLACPY( 'F', N, IV,
|
||||
$ WORK( 1 + (NB+1)*N ), N,
|
||||
$ VL( 1, KI-IV+1 ), LDVL )
|
||||
IV = 1
|
||||
ELSE
|
||||
IV = IV + 1
|
||||
END IF
|
||||
END IF
|
||||
*
|
||||
* Restore the original diagonal elements of T.
|
||||
*
|
||||
DO 120 K = KI + 1, N
|
||||
T( K, K ) = WORK( K )
|
||||
120 CONTINUE
|
||||
*
|
||||
IS = IS + 1
|
||||
130 CONTINUE
|
||||
END IF
|
||||
*
|
||||
RETURN
|
||||
*
|
||||
* End of ZTREVC3
|
||||
*
|
||||
END
|
||||
Reference in New Issue
Block a user