diff options
Diffstat (limited to 'SRC/dgemqr.f')
| -rw-r--r-- | SRC/dgemqr.f | 133 |
1 files changed, 67 insertions, 66 deletions
diff --git a/SRC/dgemqr.f b/SRC/dgemqr.f index f47e6a87..ee02d98e 100644 --- a/SRC/dgemqr.f +++ b/SRC/dgemqr.f @@ -2,20 +2,16 @@ * Definition: * =========== * -* SUBROUTINE DGEMQR( SIDE, TRANS, M, N, K, A, LDA, WORK1, -* $ LWORK1, C, LDC, WORK2, LWORK2, INFO ) +* SUBROUTINE DGEMQR( SIDE, TRANS, M, N, K, A, LDA, T, +* $ TSIZE, C, LDC, WORK, LWORK, INFO ) * * * .. Scalar Arguments .. * CHARACTER SIDE, TRANS -* INTEGER INFO, LDA, M, N, K, LDT, LWORK1, LWORK2, LDC +* INTEGER INFO, LDA, M, N, K, LDT, TSIZE, LWORK, LDC * .. * .. Array Arguments .. -* DOUBLE PRECISION A( LDA, * ), WORK1( * ), C(LDC, * ), -* $ WORK2( * ) -* .. -* -* +* DOUBLE PRECISION A( LDA, * ), T( * ), C(LDC, * ), WORK( * ) *> \par Purpose: * ============= *> @@ -65,13 +61,10 @@ *> *> \endverbatim *> -*> \param[in,out] A +*> \param[in] A *> \verbatim *> A is DOUBLE PRECISION array, dimension (LDA,K) -*> The i-th column must contain the vector which defines the -*> blockedelementary reflector H(i), for i = 1,2,...,k, as -*> returned by DGETSQR in the first k columns of -*> its array argument A. +*> Part of the data structure to represent Q as returned by SGEQR. *> \endverbatim *> *> \param[in] LDA @@ -82,16 +75,16 @@ *> if SIDE = 'R', LDA >= max(1,N). *> \endverbatim *> -*> \param[in] WORK1 +*> \param[in] T *> \verbatim -*> WORK1 is DOUBLE PRECISION array, dimension (MAX(1,LWORK1)) as -*> it is returned by GEQR. +*> T is DOUBLE PRECISION array, dimension (MAX(5,TSIZE)). +*> Part of the data structure to represent Q as returned by SGEQR. *> \endverbatim *> -*> \param[in] LWORK1 +*> \param[in] TSIZE *> \verbatim -*> LWORK1 is INTEGER -*> The dimension of the array WORK1. +*> TSIZE is INTEGER +*> The dimension of the array T. TSIZE >= 5. *> \endverbatim *> *> \param[in,out] C @@ -103,21 +96,21 @@ *> LDC is INTEGER *> The leading dimension of the array C. LDC >= max(1,M). *> -*> \param[out] WORK2 +*> \param[out] WORK *> \verbatim -*> (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK2)) +*> (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) *> *> \endverbatim -*> \param[in] LWORK2 +*> \param[in] LWORK *> \verbatim -*> LWORK2 is INTEGER -*> The dimension of the array WORK2. -*> If LWORK2 = -1, then a workspace query is assumed; the routine -*> only calculates the optimal size of the WORK2 array, returns -*> this value as the third entry of the WORK2 array (WORK2(1)), -*> and no error message related to LWORK2 is issued by XERBLA. -*> +*> LWORK is INTEGER +*> The dimension of the array WORK. +*> If LWORK = -1, then a workspace query is assumed. The routine +*> only calculates the size of the WORK array, returns this +*> value as WORK(1), and no error message related to WORK +*> is issued by XERBLA. *> \endverbatim +*> *> \param[out] INFO *> \verbatim *> INFO is INTEGER @@ -133,27 +126,35 @@ *> \author Univ. of Colorado Denver *> \author NAG Ltd. * -*> \par Further Details: -* ===================== +*> \par Further Details +* ==================== *> *> \verbatim +*> +*> These details are particular for this LAPACK implementation. Users should not +*> take them for granted. These details may change in the future, and are unlikely not +*> true for another LAPACK implementation. These details are relevant if one wants +*> to try to understand the code. They are not part of the interface. +*> +*> In this version, +*> +*> T(2): row block size (MB) +*> T(3): column block size (NB) +*> T(4:TSIZE): data structure needed for Q, computed by +*> DLATSQR or DGEQRT +*> *> Depending on the matrix dimensions M and N, and row and column *> block sizes MB and NB returned by ILAENV, GEQR will use either *> LATSQR (if the matrix is tall-and-skinny) or GEQRT to compute -*> the QR decomposition. -*> The output of LATSQR or GEQRT representing Q is stored in A and in -*> array WORK1(6:LWORK1) for later use. -*> WORK1(2:5) contains the matrix dimensions M,N and block sizes MB,NB -*> which are needed to interpret A and WORK1(6:LWORK1) for later use. -*> WORK1(1)=1 indicates that the code needed to take WORK1(2:5) and -*> decide whether LATSQR or GEQRT was used is the same as used below in -*> GEQR. For a detailed description of A and WORK1(6:LWORK1), see -*> Further Details in LATSQR or GEQRT. +*> the QR factorization. +*> This version of GEMQR will use either LAMTSQR or GEMQRT to +*> multiply matrix Q by another matrix. +*> Further Details in LATMSQR or GEMQRT. *> \endverbatim *> * ===================================================================== - SUBROUTINE DGEMQR( SIDE, TRANS, M, N, K, A, LDA, WORK1, LWORK1, - $ C, LDC, WORK2, LWORK2, INFO ) + SUBROUTINE DGEMQR( SIDE, TRANS, M, N, K, A, LDA, T, TSIZE, + $ C, LDC, WORK, LWORK, INFO ) * * -- LAPACK computational routine (version 3.5.0) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- @@ -162,11 +163,10 @@ * * .. Scalar Arguments .. CHARACTER SIDE, TRANS - INTEGER INFO, LDA, M, N, K, LWORK1, LWORK2, LDC + INTEGER INFO, LDA, M, N, K, TSIZE, LWORK, LDC * .. * .. Array Arguments .. - DOUBLE PRECISION A( LDA, * ), WORK1( * ), C(LDC, * ), - $ WORK2( * ) + DOUBLE PRECISION A( LDA, * ), T( * ), C(LDC, * ), WORK( * ) * .. * * ===================================================================== @@ -180,7 +180,7 @@ LOGICAL LSAME EXTERNAL LSAME * .. External Subroutines .. - EXTERNAL DGEMQRT, DTPMQRT, XERBLA + EXTERNAL DGEMQRT, DLAMTSQR, XERBLA * .. Intrinsic Functions .. INTRINSIC INT, MAX, MIN, MOD * .. @@ -188,14 +188,14 @@ * * Test the input arguments * - LQUERY = LWORK2.LT.0 + LQUERY = LWORK.LT.0 NOTRAN = LSAME( TRANS, 'N' ) TRAN = LSAME( TRANS, 'T' ) LEFT = LSAME( SIDE, 'L' ) RIGHT = LSAME( SIDE, 'R' ) * - MB = INT(WORK1(4)) - NB = INT(WORK1(5)) + MB = INT(T(2)) + NB = INT(T(3)) IF(LEFT) THEN LW = N * NB MN = M @@ -204,11 +204,11 @@ MN = N END IF * - IF ((MB.GT.K).AND.(MN.GT.K)) THEN - IF(MOD(MN-K, MB-K).EQ.0) THEN - NBLCKS = (MN-K)/(MB-K) + IF ( ( MB.GT.K ) .AND. ( MN.GT.K ) ) THEN + IF( MOD( MN - K, MB - K ) .EQ. 0 ) THEN + NBLCKS = ( MN - K ) / ( MB - K ) ELSE - NBLCKS = (MN-K)/(MB-K) + 1 + NBLCKS = ( MN - K ) / ( MB - K ) + 1 END IF ELSE NBLCKS = 1 @@ -227,43 +227,44 @@ INFO = -5 ELSE IF( LDA.LT.MAX( 1, K ) ) THEN INFO = -7 - ELSE IF( LWORK1.LT.MAX( 1, NB*K*NBLCKS+5 )) THEN + ELSE IF( TSIZE.LT.MAX( 1, NB*K*NBLCKS + 5 ) + $ .AND. ( .NOT.LQUERY ) ) THEN INFO = -9 - ELSE IF( LDC.LT.MAX( 1, M ).AND.MIN(M,N,K).NE.0 ) THEN + ELSE IF( LDC.LT.MAX( 1, M ) .AND. MIN( M, N, K ).NE.0 ) THEN INFO = -11 - ELSE IF(( LWORK2.LT.MAX(1,LW)).AND.(.NOT.LQUERY)) THEN + ELSE IF( ( LWORK.LT.MAX( 1, LW ) ) .AND. ( .NOT.LQUERY ) ) THEN INFO = -13 END IF * * Determine the block size if it is tall skinny or short and wide * - IF( INFO.EQ.0) THEN - WORK2(1) = LW + IF( INFO.EQ.0 ) THEN + WORK(1) = LW END IF * IF( INFO.NE.0 ) THEN CALL XERBLA( 'DGEMQR', -INFO ) RETURN - ELSE IF (LQUERY) THEN + ELSE IF ( LQUERY ) THEN RETURN END IF * * Quick return if possible * - IF( MIN(M,N,K).EQ.0 ) THEN + IF( MIN( M, N, K ).EQ.0 ) THEN RETURN END IF * - IF((LEFT.AND.M.LE.K).OR.(RIGHT.AND.N.LE.K).OR.(MB.LE.K).OR. - $ (MB.GE.MAX(M,N,K))) THEN + IF( ( LEFT .AND. M.LE.K ) .OR. ( RIGHT .AND. N.LE.K ) + $ .OR. ( MB.LE.K ) .OR. ( MB.GE.MAX( M, N, K ) ) ) THEN CALL DGEMQRT( SIDE, TRANS, M, N, K, NB, A, LDA, - $ WORK1(6), NB, C, LDC, WORK2, INFO) + $ T(4), NB, C, LDC, WORK, INFO ) ELSE - CALL DLAMTSQR( SIDE, TRANS, M, N, K, MB, NB, A, LDA, WORK1(6), - $ NB, C, LDC, WORK2, LWORK2, INFO ) + CALL DLAMTSQR( SIDE, TRANS, M, N, K, MB, NB, A, LDA, T(4), + $ NB, C, LDC, WORK, LWORK, INFO ) END IF * - WORK2(1) = LW + WORK(1) = LW * RETURN * |