--- rpl/lapack/lapack/dlarzb.f 2010/08/06 15:28:42 1.3 +++ rpl/lapack/lapack/dlarzb.f 2017/06/17 11:06:26 1.17 @@ -1,10 +1,192 @@ +*> \brief \b DLARZB applies a block reflector or its transpose to a general matrix. +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download DLARZB + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE DLARZB( SIDE, TRANS, DIRECT, STOREV, M, N, K, L, V, +* LDV, T, LDT, C, LDC, WORK, LDWORK ) +* +* .. Scalar Arguments .. +* CHARACTER DIRECT, SIDE, STOREV, TRANS +* INTEGER K, L, LDC, LDT, LDV, LDWORK, M, N +* .. +* .. Array Arguments .. +* DOUBLE PRECISION C( LDC, * ), T( LDT, * ), V( LDV, * ), +* $ WORK( LDWORK, * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> DLARZB applies a real block reflector H or its transpose H**T to +*> a real distributed M-by-N C from the left or the right. +*> +*> Currently, only STOREV = 'R' and DIRECT = 'B' are supported. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] SIDE +*> \verbatim +*> SIDE is CHARACTER*1 +*> = 'L': apply H or H**T from the Left +*> = 'R': apply H or H**T from the Right +*> \endverbatim +*> +*> \param[in] TRANS +*> \verbatim +*> TRANS is CHARACTER*1 +*> = 'N': apply H (No transpose) +*> = 'C': apply H**T (Transpose) +*> \endverbatim +*> +*> \param[in] DIRECT +*> \verbatim +*> DIRECT is CHARACTER*1 +*> Indicates how H is formed from a product of elementary +*> reflectors +*> = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet) +*> = 'B': H = H(k) . . . H(2) H(1) (Backward) +*> \endverbatim +*> +*> \param[in] STOREV +*> \verbatim +*> STOREV is CHARACTER*1 +*> Indicates how the vectors which define the elementary +*> reflectors are stored: +*> = 'C': Columnwise (not supported yet) +*> = 'R': Rowwise +*> \endverbatim +*> +*> \param[in] M +*> \verbatim +*> M is INTEGER +*> The number of rows of the matrix C. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The number of columns of the matrix C. +*> \endverbatim +*> +*> \param[in] K +*> \verbatim +*> K is INTEGER +*> The order of the matrix T (= the number of elementary +*> reflectors whose product defines the block reflector). +*> \endverbatim +*> +*> \param[in] L +*> \verbatim +*> L is INTEGER +*> The number of columns of the matrix V containing the +*> meaningful part of the Householder reflectors. +*> If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. +*> \endverbatim +*> +*> \param[in] V +*> \verbatim +*> V is DOUBLE PRECISION array, dimension (LDV,NV). +*> If STOREV = 'C', NV = K; if STOREV = 'R', NV = L. +*> \endverbatim +*> +*> \param[in] LDV +*> \verbatim +*> LDV is INTEGER +*> The leading dimension of the array V. +*> If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K. +*> \endverbatim +*> +*> \param[in] T +*> \verbatim +*> T is DOUBLE PRECISION array, dimension (LDT,K) +*> The triangular K-by-K matrix T in the representation of the +*> block reflector. +*> \endverbatim +*> +*> \param[in] LDT +*> \verbatim +*> LDT is INTEGER +*> The leading dimension of the array T. LDT >= K. +*> \endverbatim +*> +*> \param[in,out] C +*> \verbatim +*> C is DOUBLE PRECISION array, dimension (LDC,N) +*> On entry, the M-by-N matrix C. +*> On exit, C is overwritten by H*C or H**T*C or C*H or C*H**T. +*> \endverbatim +*> +*> \param[in] LDC +*> \verbatim +*> LDC is INTEGER +*> The leading dimension of the array C. LDC >= max(1,M). +*> \endverbatim +*> +*> \param[out] WORK +*> \verbatim +*> WORK is DOUBLE PRECISION array, dimension (LDWORK,K) +*> \endverbatim +*> +*> \param[in] LDWORK +*> \verbatim +*> LDWORK is INTEGER +*> The leading dimension of the array WORK. +*> If SIDE = 'L', LDWORK >= max(1,N); +*> if SIDE = 'R', LDWORK >= max(1,M). +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date December 2016 +* +*> \ingroup doubleOTHERcomputational +* +*> \par Contributors: +* ================== +*> +*> A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA +* +*> \par Further Details: +* ===================== +*> +*> \verbatim +*> \endverbatim +*> +* ===================================================================== SUBROUTINE DLARZB( SIDE, TRANS, DIRECT, STOREV, M, N, K, L, V, $ LDV, T, LDT, C, LDC, WORK, LDWORK ) * -* -- 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 +* December 2016 * * .. Scalar Arguments .. CHARACTER DIRECT, SIDE, STOREV, TRANS @@ -15,86 +197,6 @@ $ WORK( LDWORK, * ) * .. * -* Purpose -* ======= -* -* DLARZB applies a real block reflector H or its transpose H**T to -* a real distributed M-by-N C from the left or the right. -* -* Currently, only STOREV = 'R' and DIRECT = 'B' are supported. -* -* Arguments -* ========= -* -* SIDE (input) CHARACTER*1 -* = 'L': apply H or H' from the Left -* = 'R': apply H or H' from the Right -* -* TRANS (input) CHARACTER*1 -* = 'N': apply H (No transpose) -* = 'C': apply H' (Transpose) -* -* DIRECT (input) CHARACTER*1 -* Indicates how H is formed from a product of elementary -* reflectors -* = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet) -* = 'B': H = H(k) . . . H(2) H(1) (Backward) -* -* STOREV (input) CHARACTER*1 -* Indicates how the vectors which define the elementary -* reflectors are stored: -* = 'C': Columnwise (not supported yet) -* = 'R': Rowwise -* -* M (input) INTEGER -* The number of rows of the matrix C. -* -* N (input) INTEGER -* The number of columns of the matrix C. -* -* K (input) INTEGER -* The order of the matrix T (= the number of elementary -* reflectors whose product defines the block reflector). -* -* L (input) INTEGER -* The number of columns of the matrix V containing the -* meaningful part of the Householder reflectors. -* If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. -* -* V (input) DOUBLE PRECISION array, dimension (LDV,NV). -* If STOREV = 'C', NV = K; if STOREV = 'R', NV = L. -* -* LDV (input) INTEGER -* The leading dimension of the array V. -* If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K. -* -* T (input) DOUBLE PRECISION array, dimension (LDT,K) -* The triangular K-by-K matrix T in the representation of the -* block reflector. -* -* LDT (input) INTEGER -* The leading dimension of the array T. LDT >= K. -* -* C (input/output) DOUBLE PRECISION array, dimension (LDC,N) -* On entry, the M-by-N matrix C. -* On exit, C is overwritten by H*C or H'*C or C*H or C*H'. -* -* LDC (input) INTEGER -* The leading dimension of the array C. LDC >= max(1,M). -* -* WORK (workspace) DOUBLE PRECISION array, dimension (LDWORK,K) -* -* LDWORK (input) INTEGER -* The leading dimension of the array WORK. -* If SIDE = 'L', LDWORK >= max(1,N); -* if SIDE = 'R', LDWORK >= max(1,M). -* -* Further Details -* =============== -* -* Based on contributions by -* A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA -* * ===================================================================== * * .. Parameters .. @@ -140,27 +242,27 @@ * IF( LSAME( SIDE, 'L' ) ) THEN * -* Form H * C or H' * C +* Form H * C or H**T * C * -* W( 1:n, 1:k ) = C( 1:k, 1:n )' +* W( 1:n, 1:k ) = C( 1:k, 1:n )**T * DO 10 J = 1, K CALL DCOPY( N, C( J, 1 ), LDC, WORK( 1, J ), 1 ) 10 CONTINUE * * W( 1:n, 1:k ) = W( 1:n, 1:k ) + ... -* C( m-l+1:m, 1:n )' * V( 1:k, 1:l )' +* C( m-l+1:m, 1:n )**T * V( 1:k, 1:l )**T * IF( L.GT.0 ) $ CALL DGEMM( 'Transpose', 'Transpose', N, K, L, ONE, $ C( M-L+1, 1 ), LDC, V, LDV, ONE, WORK, LDWORK ) * -* W( 1:n, 1:k ) = W( 1:n, 1:k ) * T' or W( 1:m, 1:k ) * T +* W( 1:n, 1:k ) = W( 1:n, 1:k ) * T**T or W( 1:m, 1:k ) * T * CALL DTRMM( 'Right', 'Lower', TRANST, 'Non-unit', N, K, ONE, T, $ LDT, WORK, LDWORK ) * -* C( 1:k, 1:n ) = C( 1:k, 1:n ) - W( 1:n, 1:k )' +* C( 1:k, 1:n ) = C( 1:k, 1:n ) - W( 1:n, 1:k )**T * DO 30 J = 1, N DO 20 I = 1, K @@ -169,7 +271,7 @@ 30 CONTINUE * * C( m-l+1:m, 1:n ) = C( m-l+1:m, 1:n ) - ... -* V( 1:k, 1:l )' * W( 1:n, 1:k )' +* V( 1:k, 1:l )**T * W( 1:n, 1:k )**T * IF( L.GT.0 ) $ CALL DGEMM( 'Transpose', 'Transpose', L, N, K, -ONE, V, LDV, @@ -177,7 +279,7 @@ * ELSE IF( LSAME( SIDE, 'R' ) ) THEN * -* Form C * H or C * H' +* Form C * H or C * H**T * * W( 1:m, 1:k ) = C( 1:m, 1:k ) * @@ -186,13 +288,13 @@ 40 CONTINUE * * W( 1:m, 1:k ) = W( 1:m, 1:k ) + ... -* C( 1:m, n-l+1:n ) * V( 1:k, 1:l )' +* C( 1:m, n-l+1:n ) * V( 1:k, 1:l )**T * IF( L.GT.0 ) $ CALL DGEMM( 'No transpose', 'Transpose', M, K, L, ONE, $ C( 1, N-L+1 ), LDC, V, LDV, ONE, WORK, LDWORK ) * -* W( 1:m, 1:k ) = W( 1:m, 1:k ) * T or W( 1:m, 1:k ) * T' +* W( 1:m, 1:k ) = W( 1:m, 1:k ) * T or W( 1:m, 1:k ) * T**T * CALL DTRMM( 'Right', 'Lower', TRANS, 'Non-unit', M, K, ONE, T, $ LDT, WORK, LDWORK )