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template<typename T>
void larfb(char *side, char *trans, char *direct, char *storev, integer *m, integer *n, integer *k, T *v, integer *ldv, T *t, integer *ldt, T *c, integer *ldc, T *work, integer *ldwork)# LARFB applies a block reflector or its transpose to a general rectangular matrix.
Purpose:
LARFB applies a real block reflector H or its transpose H**T to a real m by n matrix C, from either the left or the right.
- Parameters:
SIDE – [in]
SIDE is CHARACTER*1
= ‘L’: apply H or H**T from the Left
= ‘R’: apply H or H**T from the RightTRANS – [in]
TRANS is CHARACTER*1
= ‘N’: apply H (No transpose)
= ‘T’: apply H**T (Transpose)DIRECT – [in]
DIRECT is CHARACTER*1
Indicates how H is formed from a product of elementary reflectors
= ‘F’: H = H(1) H(2) … H(k) (Forward)
= ‘B’: H = H(k) … H(2) H(1) (Backward)
STOREV – [in]
STOREV is CHARACTER*1
Indicates how the vectors which define the elementary reflectors are stored:
= ‘C’: Columnwise
= ‘R’: Rowwise
M – [in]
M is INTEGER
The number of rows of the matrix C.
N – [in]
N is INTEGER
The number of columns of the matrix C.
K – [in]
K is INTEGER
The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector).
If SIDE = ‘L’, M >= K >= 0;
if SIDE = ‘R’, N >= K >= 0.
V – [in]
V is REAL array, dimension
(LDV,K) if STOREV = ‘C’
(LDV,M) if STOREV = ‘R’ and SIDE = ‘L’
(LDV,N) if STOREV = ‘R’ and SIDE = ‘R’
The matrix V. See Further Details.LDV – [in]
LDV is INTEGER
The leading dimension of the array V.
If STOREV = ‘C’ and SIDE = ‘L’, LDV >= fla_max(1,M);
if STOREV = ‘C’ and SIDE = ‘R’, LDV >= fla_max(1,N);
if STOREV = ‘R’, LDV >= K.T – [in]
T is REAL array, dimension (LDT,K)
The triangular k by k matrix T in the representation of the block reflector.
LDT – [in]
LDT is INTEGER
The leading dimension of the array T. LDT >= K.
C – [inout]
C is REAL 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.LDC – [in]
LDC is INTEGER
The leading dimension of the array C. LDC >= fla_max(1,M).
WORK – [out] WORK is REAL array, dimension (LDWORK,K)
LDWORK – [in]
LDWORK is INTEGER
The leading dimension of the array WORK.
If SIDE = ‘L’, LDWORK >= fla_max(1,N);
if SIDE = ‘R’, LDWORK >= fla_max(1,M).