cgemlqt3
Part of cgemlqt.f(3).
Usage
Functions/Subroutines
CGEMLQT
Function/Subroutine Documentation
subroutine cgemlqt (character side, character trans, integer m, integer n, integer k, integer mb, complex, dimension( ldv, * ) v, integer ldv, complex, dimension( ldt, * ) t, integer ldt, complex, dimension( ldc, * ) c, integer ldc, complex, dimension( * ) work, integer info)
CGEMLQT
Purpose:
!> !> CGEMLQT overwrites the general complex M-by-N matrix C with !> !> SIDE = 'L' SIDE = 'R' !> TRANS = 'N': Q C C Q !> TRANS = 'C': Q**H C C Q**H !> !> where Q is a complex unitary matrix defined as the product of K !> elementary reflectors: !> !> Q = H(1) H(2) . . . H(K) = I - V T V**H !> !> generated using the compact WY representation as returned by CGELQT. !> !> Q is of order M if SIDE = 'L' and of order N if SIDE = 'R'. !>
Parameters
SIDE
!> SIDE is CHARACTER*1 !> = 'L': apply Q or Q**H from the Left; !> = 'R': apply Q or Q**H from the Right. !>
TRANS
!> TRANS is CHARACTER*1 !> = 'N': No transpose, apply Q; !> = 'C': Conjugate transpose, apply Q**H. !>
M
!> M is INTEGER !> The number of rows of the matrix C. M >= 0. !>
N
!> N is INTEGER !> The number of columns of the matrix C. N >= 0. !>
K
!> K is INTEGER !> The number of elementary reflectors whose product defines !> the matrix Q. !> If SIDE = 'L', M >= K >= 0; !> if SIDE = 'R', N >= K >= 0. !>
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 CGELQT. !>
V
!> V is COMPLEX array, dimension !> (LDV,M) if SIDE = 'L', !> (LDV,N) if SIDE = 'R' !> The i-th row must contain the vector which defines the !> elementary reflector H(i), for i = 1,2,...,k, as returned by !> CGELQT in the first K rows of its array argument A. !>
LDV
!> LDV is INTEGER !> The leading dimension of the array V. LDV >= max(1,K). !>
T
!> T is COMPLEX array, dimension (LDT,K) !> The upper triangular factors of the block reflectors !> as returned by CGELQT, stored as a MB-by-K matrix. !>
LDT
!> LDT is INTEGER !> The leading dimension of the array T. LDT >= MB. !>
C
!> C is COMPLEX array, dimension (LDC,N) !> On entry, the M-by-N matrix C. !> On exit, C is overwritten by Q C, Q**H C, C Q**H or C Q. !>
LDC
!> LDC is INTEGER !> The leading dimension of the array C. LDC >= max(1,M). !>
WORK
!> WORK is COMPLEX array. The dimension of !> WORK is N*MB if SIDE = 'L', or M*MB if SIDE = 'R'. !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 151 of file cgemlqt.f.
History
- Arch Linux 2026-11-01: the text shown here
- Debian 12 (Bookworm)
- Debian 11 (Bullseye)
- Debian 10 (Buster)
- Debian 9 (Stretch)