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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine dtpmlqt | ( | character | SIDE, |
character | TRANS, | ||
integer | M, | ||
integer | N, | ||
integer | K, | ||
integer | L, | ||
integer | MB, | ||
double precision, dimension( ldv, * ) | V, | ||
integer | LDV, | ||
double precision, dimension( ldt, * ) | T, | ||
integer | LDT, | ||
double precision, dimension( lda, * ) | A, | ||
integer | LDA, | ||
double precision, dimension( ldb, * ) | B, | ||
integer | LDB, | ||
double precision, dimension( * ) | WORK, | ||
integer | INFO | ||
) |
DTPMLQT
Download DTPMQRT + dependencies [TGZ] [ZIP] [TXT]
DTPMQRT applies a real orthogonal matrix Q obtained from a "triangular-pentagonal" real block reflector H to a general real matrix C, which consists of two blocks A and B.
[in] | SIDE | SIDE is CHARACTER*1 = 'L': apply Q or Q**T from the Left; = 'R': apply Q or Q**T from the Right. |
[in] | TRANS | TRANS is CHARACTER*1 = 'N': No transpose, apply Q; = 'T': Transpose, apply Q**T. |
[in] | M | M is INTEGER The number of rows of the matrix B. M >= 0. |
[in] | N | N is INTEGER The number of columns of the matrix B. N >= 0. |
[in] | K | K is INTEGER The number of elementary reflectors whose product defines the matrix Q. |
[in] | L | L is INTEGER The order of the trapezoidal part of V. K >= L >= 0. See Further Details. |
[in] | MB | MB is INTEGER The block size used for the storage of T. K >= MB >= 1. This must be the same value of MB used to generate T in DTPLQT. |
[in] | V | V is DOUBLE PRECISION array, dimension (LDA,K) The i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by DTPLQT in B. See Further Details. |
[in] | LDV | LDV is INTEGER The leading dimension of the array V. If SIDE = 'L', LDV >= max(1,M); if SIDE = 'R', LDV >= max(1,N). |
[in] | T | T is DOUBLE PRECISION array, dimension (LDT,K) The upper triangular factors of the block reflectors as returned by DTPLQT, stored as a MB-by-K matrix. |
[in] | LDT | LDT is INTEGER The leading dimension of the array T. LDT >= MB. |
[in,out] | A | A is DOUBLE PRECISION array, dimension (LDA,N) if SIDE = 'L' or (LDA,K) if SIDE = 'R' On entry, the K-by-N or M-by-K matrix A. On exit, A is overwritten by the corresponding block of Q*C or Q**T*C or C*Q or C*Q**T. See Further Details. |
[in] | LDA | LDA is INTEGER The leading dimension of the array A. If SIDE = 'L', LDC >= max(1,K); If SIDE = 'R', LDC >= max(1,M). |
[in,out] | B | B is DOUBLE PRECISION array, dimension (LDB,N) On entry, the M-by-N matrix B. On exit, B is overwritten by the corresponding block of Q*C or Q**T*C or C*Q or C*Q**T. See Further Details. |
[in] | LDB | LDB is INTEGER The leading dimension of the array B. LDB >= max(1,M). |
[out] | WORK | WORK is DOUBLE PRECISION array. The dimension of WORK is N*MB if SIDE = 'L', or M*MB if SIDE = 'R'. |
[out] | INFO | INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value |
The columns of the pentagonal matrix V contain the elementary reflectors H(1), H(2), ..., H(K); V is composed of a rectangular block V1 and a trapezoidal block V2: V = [V1] [V2]. The size of the trapezoidal block V2 is determined by the parameter L, where 0 <= L <= K; V2 is lower trapezoidal, consisting of the first L rows of a K-by-K upper triangular matrix. If L=K, V2 is lower triangular; if L=0, there is no trapezoidal block, hence V = V1 is rectangular. If SIDE = 'L': C = [A] where A is K-by-N, B is M-by-N and V is K-by-M. [B] If SIDE = 'R': C = [A B] where A is M-by-K, B is M-by-N and V is K-by-N. The real orthogonal matrix Q is formed from V and T. If TRANS='N' and SIDE='L', C is on exit replaced with Q * C. If TRANS='T' and SIDE='L', C is on exit replaced with Q**T * C. If TRANS='N' and SIDE='R', C is on exit replaced with C * Q. If TRANS='T' and SIDE='R', C is on exit replaced with C * Q**T.
Definition at line 218 of file dtpmlqt.f.