LAPACK
3.4.2
LAPACK: Linear Algebra PACKage

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Functions/Subroutines  
subroutine  dtprfb (SIDE, TRANS, DIRECT, STOREV, M, N, K, L, V, LDV, T, LDT, A, LDA, B, LDB, WORK, LDWORK) 
DTPRFB applies a real or complex "triangularpentagonal" blocked reflector to a real or complex matrix, which is composed of two blocks. 
subroutine dtprfb  (  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( lda, * )  A,  
integer  LDA,  
double precision, dimension( ldb, * )  B,  
integer  LDB,  
double precision, dimension( ldwork, * )  WORK,  
integer  LDWORK  
) 
DTPRFB applies a real or complex "triangularpentagonal" blocked reflector to a real or complex matrix, which is composed of two blocks.
Download DTPRFB + dependencies [TGZ] [ZIP] [TXT]DTPRFB applies a real "triangularpentagonal" block reflector H or its transpose H**T to a real matrix C, which is composed of two blocks A and B, either from the left or right.
[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) = 'T': 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) = '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': Columns = 'R': Rows 
[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 order of the matrix T, i.e. the number of elementary reflectors whose product defines the block reflector. K >= 0. 
[in]  L  L is INTEGER The order of the trapezoidal part of V. K >= L >= 0. See Further Details. 
[in]  V  V is DOUBLE PRECISION array, dimension (LDV,K) if STOREV = 'C' (LDV,M) if STOREV = 'R' and SIDE = 'L' (LDV,N) if STOREV = 'R' and SIDE = 'R' The pentagonal matrix V, which contains the elementary reflectors H(1), H(2), ..., H(K). See Further Details. 
[in]  LDV  LDV is INTEGER The leading dimension of the array V. If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M); if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N); if STOREV = 'R', LDV >= K. 
[in]  T  T is DOUBLE PRECISION array, dimension (LDT,K) The triangular KbyK 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]  A  A is DOUBLE PRECISION array, dimension (LDA,N) if SIDE = 'L' or (LDA,K) if SIDE = 'R' On entry, the KbyN or MbyK matrix A. On exit, A is overwritten by the corresponding block of H*C or H**T*C or C*H or C*H**T. See Futher 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 MbyN matrix B. On exit, B is overwritten by the corresponding block of H*C or H**T*C or C*H or C*H**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, dimension (LDWORK,N) if SIDE = 'L', (LDWORK,K) if SIDE = 'R'. 
[in]  LDWORK  LDWORK is INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= K; if SIDE = 'R', LDWORK >= M. 
The matrix C is a composite matrix formed from blocks A and B. The block B is of size MbyN; if SIDE = 'R', A is of size MbyK, and if SIDE = 'L', A is of size KbyN. If SIDE = 'R' and DIRECT = 'F', C = [A B]. If SIDE = 'L' and DIRECT = 'F', C = [A] [B]. If SIDE = 'R' and DIRECT = 'B', C = [B A]. If SIDE = 'L' and DIRECT = 'B', C = [B] [A]. The pentagonal matrix V is composed of a rectangular block V1 and a trapezoidal block V2. The size of the trapezoidal block is determined by the parameter L, where 0<=L<=K. If L=K, the V2 block of V is triangular; if L=0, there is no trapezoidal block, thus V = V1 is rectangular. If DIRECT = 'F' and STOREV = 'C': V = [V1] [V2]  V2 is upper trapezoidal (first L rows of KbyK upper triangular) If DIRECT = 'F' and STOREV = 'R': V = [V1 V2]  V2 is lower trapezoidal (first L columns of KbyK lower triangular) If DIRECT = 'B' and STOREV = 'C': V = [V2] [V1]  V2 is lower trapezoidal (last L rows of KbyK lower triangular) If DIRECT = 'B' and STOREV = 'R': V = [V2 V1]  V2 is upper trapezoidal (last L columns of KbyK upper triangular) If STOREV = 'C' and SIDE = 'L', V is MbyK with V2 LbyK. If STOREV = 'C' and SIDE = 'R', V is NbyK with V2 LbyK. If STOREV = 'R' and SIDE = 'L', V is KbyM with V2 KbyL. If STOREV = 'R' and SIDE = 'R', V is KbyN with V2 KbyL.
Definition at line 251 of file dtprfb.f.