diff options
Diffstat (limited to 'SRC/stplqt.f')
| -rw-r--r-- | SRC/stplqt.f | 76 |
1 files changed, 38 insertions, 38 deletions
diff --git a/SRC/stplqt.f b/SRC/stplqt.f index 56d19d71..cffb8aef 100644 --- a/SRC/stplqt.f +++ b/SRC/stplqt.f @@ -2,41 +2,41 @@ * * =========== DOCUMENTATION =========== * -* Online html documentation available at -* http://www.netlib.org/lapack/explore-html/ +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ * *> \htmlonly -*> Download DTPQRT + dependencies -*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/stplqt.f"> -*> [TGZ]</a> -*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/stplqt.f"> -*> [ZIP]</a> -*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/stplqt.f"> +*> Download DTPQRT + dependencies +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/stplqt.f"> +*> [TGZ]</a> +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/stplqt.f"> +*> [ZIP]</a> +*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/stplqt.f"> *> [TXT]</a> -*> \endhtmlonly +*> \endhtmlonly * * Definition: * =========== * * SUBROUTINE STPLQT( M, N, L, MB, A, LDA, B, LDB, T, LDT, WORK, * INFO ) -* +* * .. Scalar Arguments .. * INTEGER INFO, LDA, LDB, LDT, N, M, L, MB * .. * .. Array Arguments .. * REAL A( LDA, * ), B( LDB, * ), T( LDT, * ), WORK( * ) * .. -* +* * *> \par Purpose: * ============= *> *> \verbatim *> -*> DTPLQT computes a blocked LQ factorization of a real -*> "triangular-pentagonal" matrix C, which is composed of a -*> triangular block A and pentagonal block B, using the compact +*> DTPLQT computes a blocked LQ factorization of a real +*> "triangular-pentagonal" matrix C, which is composed of a +*> triangular block A and pentagonal block B, using the compact *> WY representation for Q. *> \endverbatim * @@ -47,7 +47,7 @@ *> \verbatim *> M is INTEGER *> The number of rows of the matrix B, and the order of the -*> triangular matrix A. +*> triangular matrix A. *> M >= 0. *> \endverbatim *> @@ -88,7 +88,7 @@ *> \param[in,out] B *> \verbatim *> B is REAL array, dimension (LDB,N) -*> On entry, the pentagonal M-by-N matrix B. The first N-L columns +*> On entry, the pentagonal M-by-N matrix B. The first N-L columns *> are rectangular, and the last L columns are lower trapezoidal. *> On exit, B contains the pentagonal matrix V. See Further Details. *> \endverbatim @@ -105,7 +105,7 @@ *> The lower triangular block reflectors stored in compact form *> as a sequence of upper triangular blocks. See Further Details. *> \endverbatim -*> +*> *> \param[in] LDT *> \verbatim *> LDT is INTEGER @@ -127,10 +127,10 @@ * Authors: * ======== * -*> \author Univ. of Tennessee -*> \author Univ. of California Berkeley -*> \author Univ. of Colorado Denver -*> \author NAG Ltd. +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. * *> \date November 2013 * @@ -141,45 +141,45 @@ *> *> \verbatim *> -*> The input matrix C is a M-by-(M+N) matrix +*> The input matrix C is a M-by-(M+N) matrix *> *> C = [ A ] [ B ] -*> +*> *> *> where A is an lower triangular N-by-N matrix, and B is M-by-N pentagonal *> matrix consisting of a M-by-(N-L) rectangular matrix B1 on left of a M-by-L *> upper trapezoidal matrix B2: -*> [ B ] = [ B1 ] [ B2 ] +*> [ B ] = [ B1 ] [ B2 ] *> [ B1 ] <- M-by-(N-L) rectangular *> [ B2 ] <- M-by-L upper trapezoidal. *> *> The lower trapezoidal matrix B2 consists of the first L columns of a -*> N-by-N lower triangular matrix, where 0 <= L <= MIN(M,N). If L=0, -*> B is rectangular M-by-N; if M=L=N, B is lower triangular. +*> N-by-N lower triangular matrix, where 0 <= L <= MIN(M,N). If L=0, +*> B is rectangular M-by-N; if M=L=N, B is lower triangular. *> *> The matrix W stores the elementary reflectors H(i) in the i-th row *> above the diagonal (of A) in the M-by-(M+N) input matrix C -*> [ C ] = [ A ] [ B ] +*> [ C ] = [ A ] [ B ] *> [ A ] <- lower triangular N-by-N *> [ B ] <- M-by-N pentagonal *> *> so that W can be represented as -*> [ W ] = [ I ] [ V ] +*> [ W ] = [ I ] [ V ] *> [ I ] <- identity, N-by-N *> [ V ] <- M-by-N, same form as B. *> *> Thus, all of information needed for W is contained on exit in B, which -*> we call V above. Note that V has the same form as B; that is, -*> [ V ] = [ V1 ] [ V2 ] +*> we call V above. Note that V has the same form as B; that is, +*> [ V ] = [ V1 ] [ V2 ] *> [ V1 ] <- M-by-(N-L) rectangular *> [ V2 ] <- M-by-L lower trapezoidal. *> -*> The rows of V represent the vectors which define the H(i)'s. +*> The rows of V represent the vectors which define the H(i)'s. *> *> The number of blocks is B = ceiling(M/MB), where each -*> block is of order MB except for the last block, which is of order +*> block is of order MB except for the last block, which is of order *> IB = M - (M-1)*MB. For each of the B blocks, a upper triangular block -*> reflector factor is computed: T1, T2, ..., TB. The MB-by-MB (and IB-by-IB +*> reflector factor is computed: T1, T2, ..., TB. The MB-by-MB (and IB-by-IB *> for the last block) T's are stored in the MB-by-N matrix T as *> *> T = [T1 T2 ... TB]. @@ -240,7 +240,7 @@ IF( M.EQ.0 .OR. N.EQ.0 ) RETURN * DO I = 1, M, MB -* +* * Compute the QR factorization of the current block * IB = MIN( M-I+1, MB ) @@ -251,20 +251,20 @@ LB = NB-N+L-I+1 END IF * - CALL STPLQT2( IB, NB, LB, A(I,I), LDA, B( I, 1 ), LDB, + CALL STPLQT2( IB, NB, LB, A(I,I), LDA, B( I, 1 ), LDB, $ T(1, I ), LDT, IINFO ) * * Update by applying H**T to B(I+IB:M,:) from the right * IF( I+IB.LE.M ) THEN CALL STPRFB( 'R', 'N', 'F', 'R', M-I-IB+1, NB, IB, LB, - $ B( I, 1 ), LDB, T( 1, I ), LDT, - $ A( I+IB, I ), LDA, B( I+IB, 1 ), LDB, + $ B( I, 1 ), LDB, T( 1, I ), LDT, + $ A( I+IB, I ), LDA, B( I+IB, 1 ), LDB, $ WORK, M-I-IB+1) END IF END DO RETURN -* +* * End of STPLQT * END |