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Diffstat (limited to 'SRC/ztrexc.f')
| -rw-r--r-- | SRC/ztrexc.f | 164 |
1 files changed, 115 insertions, 49 deletions
diff --git a/SRC/ztrexc.f b/SRC/ztrexc.f index e259e122..b1c807df 100644 --- a/SRC/ztrexc.f +++ b/SRC/ztrexc.f @@ -1,65 +1,131 @@ - SUBROUTINE ZTREXC( COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO ) -* -* -- LAPACK routine (version 3.2) -- -* -- LAPACK is a software package provided by Univ. of Tennessee, -- -* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* November 2006 -* -* .. Scalar Arguments .. - CHARACTER COMPQ - INTEGER IFST, ILST, INFO, LDQ, LDT, N -* .. -* .. Array Arguments .. - COMPLEX*16 Q( LDQ, * ), T( LDT, * ) -* .. -* +*> \brief \b ZTREXC +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +* Definition +* ========== +* +* SUBROUTINE ZTREXC( COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO ) +* +* .. Scalar Arguments .. +* CHARACTER COMPQ +* INTEGER IFST, ILST, INFO, LDQ, LDT, N +* .. +* .. Array Arguments .. +* COMPLEX*16 Q( LDQ, * ), T( LDT, * ) +* .. +* * Purpose * ======= * -* ZTREXC reorders the Schur factorization of a complex matrix -* A = Q*T*Q**H, so that the diagonal element of T with row index IFST -* is moved to row ILST. -* -* The Schur form T is reordered by a unitary similarity transformation -* Z**H*T*Z, and optionally the matrix Q of Schur vectors is updated by -* postmultplying it with Z. +*>\details \b Purpose: +*>\verbatim +*> +*> ZTREXC reorders the Schur factorization of a complex matrix +*> A = Q*T*Q**H, so that the diagonal element of T with row index IFST +*> is moved to row ILST. +*> +*> The Schur form T is reordered by a unitary similarity transformation +*> Z**H*T*Z, and optionally the matrix Q of Schur vectors is updated by +*> postmultplying it with Z. +*> +*>\endverbatim * * Arguments * ========= * -* COMPQ (input) CHARACTER*1 -* = 'V': update the matrix Q of Schur vectors; -* = 'N': do not update Q. -* -* N (input) INTEGER -* The order of the matrix T. N >= 0. +*> \param[in] COMPQ +*> \verbatim +*> COMPQ is CHARACTER*1 +*> = 'V': update the matrix Q of Schur vectors; +*> = 'N': do not update Q. +*> \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) +*> On entry, the upper triangular matrix T. +*> On exit, the reordered upper triangular matrix. +*> \endverbatim +*> +*> \param[in] LDT +*> \verbatim +*> LDT is INTEGER +*> The leading dimension of the array T. LDT >= max(1,N). +*> \endverbatim +*> +*> \param[in,out] Q +*> \verbatim +*> Q is COMPLEX*16 array, dimension (LDQ,N) +*> On entry, if COMPQ = 'V', the matrix Q of Schur vectors. +*> On exit, if COMPQ = 'V', Q has been postmultiplied by the +*> unitary transformation matrix Z which reorders T. +*> If COMPQ = 'N', Q is not referenced. +*> \endverbatim +*> +*> \param[in] LDQ +*> \verbatim +*> LDQ is INTEGER +*> The leading dimension of the array Q. LDQ >= max(1,N). +*> \endverbatim +*> +*> \param[in] IFST +*> \verbatim +*> IFST is INTEGER +*> \param[in] ILST +*> \verbatim +*> ILST is INTEGER +*> Specify the reordering of the diagonal elements of T: +*> The element with row index IFST is moved to row ILST by a +*> sequence of transpositions between adjacent elements. +*> 1 <= IFST <= N; 1 <= ILST <= N. +*> \endverbatim +*> \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 +* ======= * -* T (input/output) COMPLEX*16 array, dimension (LDT,N) -* On entry, the upper triangular matrix T. -* On exit, the reordered upper triangular matrix. +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. * -* LDT (input) INTEGER -* The leading dimension of the array T. LDT >= max(1,N). +*> \date November 2011 * -* Q (input/output) COMPLEX*16 array, dimension (LDQ,N) -* On entry, if COMPQ = 'V', the matrix Q of Schur vectors. -* On exit, if COMPQ = 'V', Q has been postmultiplied by the -* unitary transformation matrix Z which reorders T. -* If COMPQ = 'N', Q is not referenced. +*> \ingroup complex16OTHERcomputational * -* LDQ (input) INTEGER -* The leading dimension of the array Q. LDQ >= max(1,N). +* ===================================================================== + SUBROUTINE ZTREXC( COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO ) * -* IFST (input) INTEGER -* ILST (input) INTEGER -* Specify the reordering of the diagonal elements of T: -* The element with row index IFST is moved to row ILST by a -* sequence of transpositions between adjacent elements. -* 1 <= IFST <= N; 1 <= ILST <= N. +* -- LAPACK computational routine (version 3.2) -- +* -- LAPACK is a software package provided by Univ. of Tennessee, -- +* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- +* November 2011 * -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value +* .. Scalar Arguments .. + CHARACTER COMPQ + INTEGER IFST, ILST, INFO, LDQ, LDT, N +* .. +* .. Array Arguments .. + COMPLEX*16 Q( LDQ, * ), T( LDT, * ) +* .. * * ===================================================================== * |