table of contents
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/ztprfb.f(3) | Library Functions Manual | /home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/ztprfb.f(3) |
NAME¶
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/ztprfb.f
SYNOPSIS¶
Functions/Subroutines¶
subroutine ZTPRFB (side, trans, direct, storev, m, n, k, l,
v, ldv, t, ldt, a, lda, b, ldb, work, ldwork)
ZTPRFB applies a complex
triangular-pentagonal"blockreflectortoacomplexmatrix,whichiscomposedoftwoblocks.
Function/Subroutine Documentation¶
subroutine ZTPRFB (character side, character trans, character direct, character storev, integer m, integer n, integer k, integer l, complex*16, dimension( ldv, * ) v, integer ldv, complex*16, dimension( ldt, * ) t, integer ldt, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( ldb, * ) b, integer ldb, complex*16, dimension( ldwork, * ) work, integer ldwork)¶
ZTPRFB applies a complex "triangular-pentagonal" block reflector to a complex matrix, which is composed of two blocks.
Purpose:
!> !> ZTPRFB applies a complex block reflector H or its !> conjugate transpose H**H to a complex matrix C, which is composed of two !> blocks A and B, either from the left or right. !> !>
Parameters
SIDE
!> SIDE is CHARACTER*1 !> = 'L': apply H or H**H from the Left !> = 'R': apply H or H**H from the Right !>
TRANS
!> TRANS is CHARACTER*1 !> = 'N': apply H (No transpose) !> = 'C': apply H**H (Conjugate transpose) !>
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) !>
STOREV
!> STOREV is CHARACTER*1 !> Indicates how the vectors which define the elementary !> reflectors are stored: !> = 'C': Columns !> = 'R': Rows !>
M
!> M is INTEGER !> The number of rows of the matrix B. !> M >= 0. !>
N
!> N is INTEGER !> The number of columns of the matrix B. !> N >= 0. !>
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. !>
L
!> L is INTEGER !> The order of the trapezoidal part of V. !> K >= L >= 0. See Further Details. !>
V
!> V is COMPLEX*16 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. !>
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. !>
T
!> T is COMPLEX*16 array, dimension (LDT,K) !> The triangular K-by-K matrix T in the representation of the !> block reflector. !>
LDT
!> LDT is INTEGER !> The leading dimension of the array T. !> LDT >= K. !>
A
!> A is COMPLEX*16 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 !> H*C or H**H*C or C*H or C*H**H. See Further Details. !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. !> If SIDE = 'L', LDA >= max(1,K); !> If SIDE = 'R', LDA >= max(1,M). !>
B
!> B is COMPLEX*16 array, dimension (LDB,N) !> On entry, the M-by-N matrix B. !> On exit, B is overwritten by the corresponding block of !> H*C or H**H*C or C*H or C*H**H. See Further Details. !>
LDB
!> LDB is INTEGER !> The leading dimension of the array B. !> LDB >= max(1,M). !>
WORK
!> WORK is COMPLEX*16 array, dimension !> (LDWORK,N) if SIDE = 'L', !> (LDWORK,K) if SIDE = 'R'. !>
LDWORK
!> LDWORK is INTEGER !> The leading dimension of the array WORK. !> If SIDE = 'L', LDWORK >= K; !> if SIDE = 'R', LDWORK >= M. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Further Details:
!> !> The matrix C is a composite matrix formed from blocks A and B. !> The block B is of size M-by-N; if SIDE = 'R', A is of size M-by-K, !> and if SIDE = 'L', A is of size K-by-N. !> !> 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 K-by-K upper triangular) !> !> If DIRECT = 'F' and STOREV = 'R': V = [V1 V2] !> !> - V2 is lower trapezoidal (first L columns of K-by-K lower triangular) !> !> If DIRECT = 'B' and STOREV = 'C': V = [V2] !> [V1] !> - V2 is lower trapezoidal (last L rows of K-by-K lower triangular) !> !> If DIRECT = 'B' and STOREV = 'R': V = [V2 V1] !> !> - V2 is upper trapezoidal (last L columns of K-by-K upper triangular) !> !> If STOREV = 'C' and SIDE = 'L', V is M-by-K with V2 L-by-K. !> !> If STOREV = 'C' and SIDE = 'R', V is N-by-K with V2 L-by-K. !> !> If STOREV = 'R' and SIDE = 'L', V is K-by-M with V2 K-by-L. !> !> If STOREV = 'R' and SIDE = 'R', V is K-by-N with V2 K-by-L. !>
Definition at line 249 of file ztprfb.f.
Author¶
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