--- rpl/lapack/lapack/dlaqr5.f 2011/07/22 07:38:07 1.9 +++ rpl/lapack/lapack/dlaqr5.f 2011/11/21 20:42:57 1.10 @@ -1,11 +1,268 @@ +*> \brief \b DLAQR5 +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download DLAQR5 + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE DLAQR5( WANTT, WANTZ, KACC22, N, KTOP, KBOT, NSHFTS, +* SR, SI, H, LDH, ILOZ, IHIZ, Z, LDZ, V, LDV, U, +* LDU, NV, WV, LDWV, NH, WH, LDWH ) +* +* .. Scalar Arguments .. +* INTEGER IHIZ, ILOZ, KACC22, KBOT, KTOP, LDH, LDU, LDV, +* $ LDWH, LDWV, LDZ, N, NH, NSHFTS, NV +* LOGICAL WANTT, WANTZ +* .. +* .. Array Arguments .. +* DOUBLE PRECISION H( LDH, * ), SI( * ), SR( * ), U( LDU, * ), +* $ V( LDV, * ), WH( LDWH, * ), WV( LDWV, * ), +* $ Z( LDZ, * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> DLAQR5, called by DLAQR0, performs a +*> single small-bulge multi-shift QR sweep. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] WANTT +*> \verbatim +*> WANTT is logical scalar +*> WANTT = .true. if the quasi-triangular Schur factor +*> is being computed. WANTT is set to .false. otherwise. +*> \endverbatim +*> +*> \param[in] WANTZ +*> \verbatim +*> WANTZ is logical scalar +*> WANTZ = .true. if the orthogonal Schur factor is being +*> computed. WANTZ is set to .false. otherwise. +*> \endverbatim +*> +*> \param[in] KACC22 +*> \verbatim +*> KACC22 is integer with value 0, 1, or 2. +*> Specifies the computation mode of far-from-diagonal +*> orthogonal updates. +*> = 0: DLAQR5 does not accumulate reflections and does not +*> use matrix-matrix multiply to update far-from-diagonal +*> matrix entries. +*> = 1: DLAQR5 accumulates reflections and uses matrix-matrix +*> multiply to update the far-from-diagonal matrix entries. +*> = 2: DLAQR5 accumulates reflections, uses matrix-matrix +*> multiply to update the far-from-diagonal matrix entries, +*> and takes advantage of 2-by-2 block structure during +*> matrix multiplies. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is integer scalar +*> N is the order of the Hessenberg matrix H upon which this +*> subroutine operates. +*> \endverbatim +*> +*> \param[in] KTOP +*> \verbatim +*> KTOP is integer scalar +*> \endverbatim +*> +*> \param[in] KBOT +*> \verbatim +*> KBOT is integer scalar +*> These are the first and last rows and columns of an +*> isolated diagonal block upon which the QR sweep is to be +*> applied. It is assumed without a check that +*> either KTOP = 1 or H(KTOP,KTOP-1) = 0 +*> and +*> either KBOT = N or H(KBOT+1,KBOT) = 0. +*> \endverbatim +*> +*> \param[in] NSHFTS +*> \verbatim +*> NSHFTS is integer scalar +*> NSHFTS gives the number of simultaneous shifts. NSHFTS +*> must be positive and even. +*> \endverbatim +*> +*> \param[in,out] SR +*> \verbatim +*> SR is DOUBLE PRECISION array of size (NSHFTS) +*> \endverbatim +*> +*> \param[in,out] SI +*> \verbatim +*> SI is DOUBLE PRECISION array of size (NSHFTS) +*> SR contains the real parts and SI contains the imaginary +*> parts of the NSHFTS shifts of origin that define the +*> multi-shift QR sweep. On output SR and SI may be +*> reordered. +*> \endverbatim +*> +*> \param[in,out] H +*> \verbatim +*> H is DOUBLE PRECISION array of size (LDH,N) +*> On input H contains a Hessenberg matrix. On output a +*> multi-shift QR sweep with shifts SR(J)+i*SI(J) is applied +*> to the isolated diagonal block in rows and columns KTOP +*> through KBOT. +*> \endverbatim +*> +*> \param[in] LDH +*> \verbatim +*> LDH is integer scalar +*> LDH is the leading dimension of H just as declared in the +*> calling procedure. LDH.GE.MAX(1,N). +*> \endverbatim +*> +*> \param[in] ILOZ +*> \verbatim +*> ILOZ is INTEGER +*> \endverbatim +*> +*> \param[in] IHIZ +*> \verbatim +*> IHIZ is INTEGER +*> Specify the rows of Z to which transformations must be +*> applied if WANTZ is .TRUE.. 1 .LE. ILOZ .LE. IHIZ .LE. N +*> \endverbatim +*> +*> \param[in,out] Z +*> \verbatim +*> Z is DOUBLE PRECISION array of size (LDZ,IHI) +*> If WANTZ = .TRUE., then the QR Sweep orthogonal +*> similarity transformation is accumulated into +*> Z(ILOZ:IHIZ,ILO:IHI) from the right. +*> If WANTZ = .FALSE., then Z is unreferenced. +*> \endverbatim +*> +*> \param[in] LDZ +*> \verbatim +*> LDZ is integer scalar +*> LDA is the leading dimension of Z just as declared in +*> the calling procedure. LDZ.GE.N. +*> \endverbatim +*> +*> \param[out] V +*> \verbatim +*> V is DOUBLE PRECISION array of size (LDV,NSHFTS/2) +*> \endverbatim +*> +*> \param[in] LDV +*> \verbatim +*> LDV is integer scalar +*> LDV is the leading dimension of V as declared in the +*> calling procedure. LDV.GE.3. +*> \endverbatim +*> +*> \param[out] U +*> \verbatim +*> U is DOUBLE PRECISION array of size +*> (LDU,3*NSHFTS-3) +*> \endverbatim +*> +*> \param[in] LDU +*> \verbatim +*> LDU is integer scalar +*> LDU is the leading dimension of U just as declared in the +*> in the calling subroutine. LDU.GE.3*NSHFTS-3. +*> \endverbatim +*> +*> \param[in] NH +*> \verbatim +*> NH is integer scalar +*> NH is the number of columns in array WH available for +*> workspace. NH.GE.1. +*> \endverbatim +*> +*> \param[out] WH +*> \verbatim +*> WH is DOUBLE PRECISION array of size (LDWH,NH) +*> \endverbatim +*> +*> \param[in] LDWH +*> \verbatim +*> LDWH is integer scalar +*> Leading dimension of WH just as declared in the +*> calling procedure. LDWH.GE.3*NSHFTS-3. +*> \endverbatim +*> +*> \param[in] NV +*> \verbatim +*> NV is integer scalar +*> NV is the number of rows in WV agailable for workspace. +*> NV.GE.1. +*> \endverbatim +*> +*> \param[out] WV +*> \verbatim +*> WV is DOUBLE PRECISION array of size +*> (LDWV,3*NSHFTS-3) +*> \endverbatim +*> +*> \param[in] LDWV +*> \verbatim +*> LDWV is integer scalar +*> LDWV is the leading dimension of WV as declared in the +*> in the calling subroutine. LDWV.GE.NV. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2011 +* +*> \ingroup doubleOTHERauxiliary +* +*> \par Contributors: +* ================== +*> +*> Karen Braman and Ralph Byers, Department of Mathematics, +*> University of Kansas, USA +* +*> \par References: +* ================ +*> +*> K. Braman, R. Byers and R. Mathias, The Multi-Shift QR +*> Algorithm Part I: Maintaining Well Focused Shifts, and Level 3 +*> Performance, SIAM Journal of Matrix Analysis, volume 23, pages +*> 929--947, 2002. +*> +* ===================================================================== SUBROUTINE DLAQR5( WANTT, WANTZ, KACC22, N, KTOP, KBOT, NSHFTS, $ SR, SI, H, LDH, ILOZ, IHIZ, Z, LDZ, V, LDV, U, $ LDU, NV, WV, LDWV, NH, WH, LDWH ) * -* -- LAPACK auxiliary routine (version 3.3.0) -- +* -- LAPACK auxiliary 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 2010 +* November 2011 * * .. Scalar Arguments .. INTEGER IHIZ, ILOZ, KACC22, KBOT, KTOP, LDH, LDU, LDV, @@ -18,127 +275,7 @@ $ Z( LDZ, * ) * .. * -* This auxiliary subroutine called by DLAQR0 performs a -* single small-bulge multi-shift QR sweep. -* -* WANTT (input) logical scalar -* WANTT = .true. if the quasi-triangular Schur factor -* is being computed. WANTT is set to .false. otherwise. -* -* WANTZ (input) logical scalar -* WANTZ = .true. if the orthogonal Schur factor is being -* computed. WANTZ is set to .false. otherwise. -* -* KACC22 (input) integer with value 0, 1, or 2. -* Specifies the computation mode of far-from-diagonal -* orthogonal updates. -* = 0: DLAQR5 does not accumulate reflections and does not -* use matrix-matrix multiply to update far-from-diagonal -* matrix entries. -* = 1: DLAQR5 accumulates reflections and uses matrix-matrix -* multiply to update the far-from-diagonal matrix entries. -* = 2: DLAQR5 accumulates reflections, uses matrix-matrix -* multiply to update the far-from-diagonal matrix entries, -* and takes advantage of 2-by-2 block structure during -* matrix multiplies. -* -* N (input) integer scalar -* N is the order of the Hessenberg matrix H upon which this -* subroutine operates. -* -* KTOP (input) integer scalar -* KBOT (input) integer scalar -* These are the first and last rows and columns of an -* isolated diagonal block upon which the QR sweep is to be -* applied. It is assumed without a check that -* either KTOP = 1 or H(KTOP,KTOP-1) = 0 -* and -* either KBOT = N or H(KBOT+1,KBOT) = 0. -* -* NSHFTS (input) integer scalar -* NSHFTS gives the number of simultaneous shifts. NSHFTS -* must be positive and even. -* -* SR (input/output) DOUBLE PRECISION array of size (NSHFTS) -* SI (input/output) DOUBLE PRECISION array of size (NSHFTS) -* SR contains the real parts and SI contains the imaginary -* parts of the NSHFTS shifts of origin that define the -* multi-shift QR sweep. On output SR and SI may be -* reordered. -* -* H (input/output) DOUBLE PRECISION array of size (LDH,N) -* On input H contains a Hessenberg matrix. On output a -* multi-shift QR sweep with shifts SR(J)+i*SI(J) is applied -* to the isolated diagonal block in rows and columns KTOP -* through KBOT. -* -* LDH (input) integer scalar -* LDH is the leading dimension of H just as declared in the -* calling procedure. LDH.GE.MAX(1,N). -* -* ILOZ (input) INTEGER -* IHIZ (input) INTEGER -* Specify the rows of Z to which transformations must be -* applied if WANTZ is .TRUE.. 1 .LE. ILOZ .LE. IHIZ .LE. N -* -* Z (input/output) DOUBLE PRECISION array of size (LDZ,IHI) -* If WANTZ = .TRUE., then the QR Sweep orthogonal -* similarity transformation is accumulated into -* Z(ILOZ:IHIZ,ILO:IHI) from the right. -* If WANTZ = .FALSE., then Z is unreferenced. -* -* LDZ (input) integer scalar -* LDA is the leading dimension of Z just as declared in -* the calling procedure. LDZ.GE.N. -* -* V (workspace) DOUBLE PRECISION array of size (LDV,NSHFTS/2) -* -* LDV (input) integer scalar -* LDV is the leading dimension of V as declared in the -* calling procedure. LDV.GE.3. -* -* U (workspace) DOUBLE PRECISION array of size -* (LDU,3*NSHFTS-3) -* -* LDU (input) integer scalar -* LDU is the leading dimension of U just as declared in the -* in the calling subroutine. LDU.GE.3*NSHFTS-3. -* -* NH (input) integer scalar -* NH is the number of columns in array WH available for -* workspace. NH.GE.1. -* -* WH (workspace) DOUBLE PRECISION array of size (LDWH,NH) -* -* LDWH (input) integer scalar -* Leading dimension of WH just as declared in the -* calling procedure. LDWH.GE.3*NSHFTS-3. -* -* NV (input) integer scalar -* NV is the number of rows in WV agailable for workspace. -* NV.GE.1. -* -* WV (workspace) DOUBLE PRECISION array of size -* (LDWV,3*NSHFTS-3) -* -* LDWV (input) integer scalar -* LDWV is the leading dimension of WV as declared in the -* in the calling subroutine. LDWV.GE.NV. -* -* ================================================================ -* Based on contributions by -* Karen Braman and Ralph Byers, Department of Mathematics, -* University of Kansas, USA -* -* ================================================================ -* Reference: -* -* K. Braman, R. Byers and R. Mathias, The Multi-Shift QR -* Algorithm Part I: Maintaining Well Focused Shifts, and -* Level 3 Performance, SIAM Journal of Matrix Analysis, -* volume 23, pages 929--947, 2002. -* -* ================================================================ +* ================================================================ * .. Parameters .. DOUBLE PRECISION ZERO, ONE PARAMETER ( ZERO = 0.0d0, ONE = 1.0d0 )