--- rpl/lapack/lapack/dorgbr.f 2010/12/21 13:53:34 1.7 +++ rpl/lapack/lapack/dorgbr.f 2017/06/17 11:06:29 1.17 @@ -1,9 +1,166 @@ +*> \brief \b DORGBR +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download DORGBR + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE DORGBR( VECT, M, N, K, A, LDA, TAU, WORK, LWORK, INFO ) +* +* .. Scalar Arguments .. +* CHARACTER VECT +* INTEGER INFO, K, LDA, LWORK, M, N +* .. +* .. Array Arguments .. +* DOUBLE PRECISION A( LDA, * ), TAU( * ), WORK( * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> DORGBR generates one of the real orthogonal matrices Q or P**T +*> determined by DGEBRD when reducing a real matrix A to bidiagonal +*> form: A = Q * B * P**T. Q and P**T are defined as products of +*> elementary reflectors H(i) or G(i) respectively. +*> +*> If VECT = 'Q', A is assumed to have been an M-by-K matrix, and Q +*> is of order M: +*> if m >= k, Q = H(1) H(2) . . . H(k) and DORGBR returns the first n +*> columns of Q, where m >= n >= k; +*> if m < k, Q = H(1) H(2) . . . H(m-1) and DORGBR returns Q as an +*> M-by-M matrix. +*> +*> If VECT = 'P', A is assumed to have been a K-by-N matrix, and P**T +*> is of order N: +*> if k < n, P**T = G(k) . . . G(2) G(1) and DORGBR returns the first m +*> rows of P**T, where n >= m >= k; +*> if k >= n, P**T = G(n-1) . . . G(2) G(1) and DORGBR returns P**T as +*> an N-by-N matrix. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] VECT +*> \verbatim +*> VECT is CHARACTER*1 +*> Specifies whether the matrix Q or the matrix P**T is +*> required, as defined in the transformation applied by DGEBRD: +*> = 'Q': generate Q; +*> = 'P': generate P**T. +*> \endverbatim +*> +*> \param[in] M +*> \verbatim +*> M is INTEGER +*> The number of rows of the matrix Q or P**T to be returned. +*> M >= 0. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The number of columns of the matrix Q or P**T to be returned. +*> N >= 0. +*> If VECT = 'Q', M >= N >= min(M,K); +*> if VECT = 'P', N >= M >= min(N,K). +*> \endverbatim +*> +*> \param[in] K +*> \verbatim +*> K is INTEGER +*> If VECT = 'Q', the number of columns in the original M-by-K +*> matrix reduced by DGEBRD. +*> If VECT = 'P', the number of rows in the original K-by-N +*> matrix reduced by DGEBRD. +*> K >= 0. +*> \endverbatim +*> +*> \param[in,out] A +*> \verbatim +*> A is DOUBLE PRECISION array, dimension (LDA,N) +*> On entry, the vectors which define the elementary reflectors, +*> as returned by DGEBRD. +*> On exit, the M-by-N matrix Q or P**T. +*> \endverbatim +*> +*> \param[in] LDA +*> \verbatim +*> LDA is INTEGER +*> The leading dimension of the array A. LDA >= max(1,M). +*> \endverbatim +*> +*> \param[in] TAU +*> \verbatim +*> TAU is DOUBLE PRECISION array, dimension +*> (min(M,K)) if VECT = 'Q' +*> (min(N,K)) if VECT = 'P' +*> TAU(i) must contain the scalar factor of the elementary +*> reflector H(i) or G(i), which determines Q or P**T, as +*> returned by DGEBRD in its array argument TAUQ or TAUP. +*> \endverbatim +*> +*> \param[out] WORK +*> \verbatim +*> WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)) +*> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. +*> \endverbatim +*> +*> \param[in] LWORK +*> \verbatim +*> LWORK is INTEGER +*> The dimension of the array WORK. LWORK >= max(1,min(M,N)). +*> For optimum performance LWORK >= min(M,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] 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 April 2012 +* +*> \ingroup doubleGBcomputational +* +* ===================================================================== SUBROUTINE DORGBR( VECT, M, N, K, A, LDA, TAU, WORK, LWORK, INFO ) * -* -- LAPACK routine (version 3.2) -- +* -- LAPACK computational routine (version 3.7.0) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* November 2006 +* April 2012 * * .. Scalar Arguments .. CHARACTER VECT @@ -13,86 +170,6 @@ DOUBLE PRECISION A( LDA, * ), TAU( * ), WORK( * ) * .. * -* Purpose -* ======= -* -* DORGBR generates one of the real orthogonal matrices Q or P**T -* determined by DGEBRD when reducing a real matrix A to bidiagonal -* form: A = Q * B * P**T. Q and P**T are defined as products of -* elementary reflectors H(i) or G(i) respectively. -* -* If VECT = 'Q', A is assumed to have been an M-by-K matrix, and Q -* is of order M: -* if m >= k, Q = H(1) H(2) . . . H(k) and DORGBR returns the first n -* columns of Q, where m >= n >= k; -* if m < k, Q = H(1) H(2) . . . H(m-1) and DORGBR returns Q as an -* M-by-M matrix. -* -* If VECT = 'P', A is assumed to have been a K-by-N matrix, and P**T -* is of order N: -* if k < n, P**T = G(k) . . . G(2) G(1) and DORGBR returns the first m -* rows of P**T, where n >= m >= k; -* if k >= n, P**T = G(n-1) . . . G(2) G(1) and DORGBR returns P**T as -* an N-by-N matrix. -* -* Arguments -* ========= -* -* VECT (input) CHARACTER*1 -* Specifies whether the matrix Q or the matrix P**T is -* required, as defined in the transformation applied by DGEBRD: -* = 'Q': generate Q; -* = 'P': generate P**T. -* -* M (input) INTEGER -* The number of rows of the matrix Q or P**T to be returned. -* M >= 0. -* -* N (input) INTEGER -* The number of columns of the matrix Q or P**T to be returned. -* N >= 0. -* If VECT = 'Q', M >= N >= min(M,K); -* if VECT = 'P', N >= M >= min(N,K). -* -* K (input) INTEGER -* If VECT = 'Q', the number of columns in the original M-by-K -* matrix reduced by DGEBRD. -* If VECT = 'P', the number of rows in the original K-by-N -* matrix reduced by DGEBRD. -* K >= 0. -* -* A (input/output) DOUBLE PRECISION array, dimension (LDA,N) -* On entry, the vectors which define the elementary reflectors, -* as returned by DGEBRD. -* On exit, the M-by-N matrix Q or P**T. -* -* LDA (input) INTEGER -* The leading dimension of the array A. LDA >= max(1,M). -* -* TAU (input) DOUBLE PRECISION array, dimension -* (min(M,K)) if VECT = 'Q' -* (min(N,K)) if VECT = 'P' -* TAU(i) must contain the scalar factor of the elementary -* reflector H(i) or G(i), which determines Q or P**T, as -* returned by DGEBRD in its array argument TAUQ or TAUP. -* -* WORK (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) -* On exit, if INFO = 0, WORK(1) returns the optimal LWORK. -* -* LWORK (input) INTEGER -* The dimension of the array WORK. LWORK >= max(1,min(M,N)). -* For optimum performance LWORK >= min(M,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. -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value -* * ===================================================================== * * .. Parameters .. @@ -101,12 +178,11 @@ * .. * .. Local Scalars .. LOGICAL LQUERY, WANTQ - INTEGER I, IINFO, J, LWKOPT, MN, NB + INTEGER I, IINFO, J, LWKOPT, MN * .. * .. External Functions .. LOGICAL LSAME - INTEGER ILAENV - EXTERNAL LSAME, ILAENV + EXTERNAL LSAME * .. * .. External Subroutines .. EXTERNAL DORGLQ, DORGQR, XERBLA @@ -139,19 +215,35 @@ END IF * IF( INFO.EQ.0 ) THEN + WORK( 1 ) = 1 IF( WANTQ ) THEN - NB = ILAENV( 1, 'DORGQR', ' ', M, N, K, -1 ) + IF( M.GE.K ) THEN + CALL DORGQR( M, N, K, A, LDA, TAU, WORK, -1, IINFO ) + ELSE + IF( M.GT.1 ) THEN + CALL DORGQR( M-1, M-1, M-1, A( 2, 2 ), LDA, TAU, WORK, + $ -1, IINFO ) + END IF + END IF ELSE - NB = ILAENV( 1, 'DORGLQ', ' ', M, N, K, -1 ) + IF( K.LT.N ) THEN + CALL DORGLQ( M, N, K, A, LDA, TAU, WORK, -1, IINFO ) + ELSE + IF( N.GT.1 ) THEN + CALL DORGLQ( N-1, N-1, N-1, A( 2, 2 ), LDA, TAU, WORK, + $ -1, IINFO ) + END IF + END IF END IF - LWKOPT = MAX( 1, MN )*NB - WORK( 1 ) = LWKOPT + LWKOPT = WORK( 1 ) + LWKOPT = MAX (LWKOPT, MN) END IF * IF( INFO.NE.0 ) THEN CALL XERBLA( 'DORGBR', -INFO ) RETURN ELSE IF( LQUERY ) THEN + WORK( 1 ) = LWKOPT RETURN END IF * @@ -201,7 +293,7 @@ END IF ELSE * -* Form P', determined by a call to DGEBRD to reduce a k-by-n +* Form P**T, determined by a call to DGEBRD to reduce a k-by-n * matrix * IF( K.LT.N ) THEN @@ -215,7 +307,7 @@ * If k >= n, assume m = n * * Shift the vectors which define the elementary reflectors one -* row downward, and set the first row and column of P' to +* row downward, and set the first row and column of P**T to * those of the unit matrix * A( 1, 1 ) = ONE @@ -230,7 +322,7 @@ 60 CONTINUE IF( N.GT.1 ) THEN * -* Form P'(2:n,2:n) +* Form P**T(2:n,2:n) * CALL DORGLQ( N-1, N-1, N-1, A( 2, 2 ), LDA, TAU, WORK, $ LWORK, IINFO )