LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
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subroutine dlarzb | ( | character | side, |
character | trans, | ||
character | direct, | ||
character | storev, | ||
integer | m, | ||
integer | n, | ||
integer | k, | ||
integer | l, | ||
double precision, dimension( ldv, * ) | v, | ||
integer | ldv, | ||
double precision, dimension( ldt, * ) | t, | ||
integer | ldt, | ||
double precision, dimension( ldc, * ) | c, | ||
integer | ldc, | ||
double precision, dimension( ldwork, * ) | work, | ||
integer | ldwork | ||
) |
DLARZB applies a block reflector or its transpose to a general matrix.
Download DLARZB + dependencies [TGZ] [ZIP] [TXT]
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.
[in] | SIDE | SIDE is CHARACTER*1 = 'L': apply H or H**T from the Left = 'R': apply H or H**T from the Right |
[in] | TRANS | TRANS is CHARACTER*1 = 'N': apply H (No transpose) = 'C': apply H**T (Transpose) |
[in] | DIRECT | 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) |
[in] | STOREV | STOREV is CHARACTER*1 Indicates how the vectors which define the elementary reflectors are stored: = 'C': Columnwise (not supported yet) = 'R': Rowwise |
[in] | M | M is INTEGER The number of rows of the matrix C. |
[in] | N | N is INTEGER The number of columns of the matrix C. |
[in] | K | K is INTEGER The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector). |
[in] | L | 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. |
[in] | V | V is DOUBLE PRECISION array, dimension (LDV,NV). If STOREV = 'C', NV = K; if STOREV = 'R', NV = L. |
[in] | LDV | LDV is INTEGER The leading dimension of the array V. If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K. |
[in] | T | T is DOUBLE PRECISION array, dimension (LDT,K) The triangular K-by-K matrix T in the representation of the block reflector. |
[in] | LDT | LDT is INTEGER The leading dimension of the array T. LDT >= K. |
[in,out] | C | 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. |
[in] | LDC | LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). |
[out] | WORK | WORK is DOUBLE PRECISION array, dimension (LDWORK,K) |
[in] | LDWORK | LDWORK is INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M). |
Definition at line 181 of file dlarzb.f.