cunml2.f3
Usage
Functions/Subroutines
subroutine cunml2 (side, trans, m, n, k, a, lda, tau, c, ldc, work, info)
CUNML2 multiplies a general matrix by the unitary matrix from a LQ factorization determined by cgelqf (unblocked algorithm).
Function/Subroutine Documentation
subroutine cunml2 (character side, character trans, integer m, integer n, integer k, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) tau, complex, dimension( ldc, * ) c, integer ldc, complex, dimension( * ) work, integer info)
CUNML2 multiplies a general matrix by the unitary matrix from a LQ factorization determined by cgelqf (unblocked algorithm).
Purpose:
!> !> CUNML2 overwrites the general complex m-by-n matrix C with !> !> Q * C if SIDE = 'L' and TRANS = 'N', or !> !> Q**H* C if SIDE = 'L' and TRANS = 'C', or !> !> C * Q if SIDE = 'R' and TRANS = 'N', or !> !> C * Q**H if SIDE = 'R' and TRANS = 'C', !> !> where Q is a complex unitary matrix defined as the product of k !> elementary reflectors !> !> Q = H(k)**H . . . H(2)**H H(1)**H !> !> as returned by CGELQF. 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': apply Q (No transpose) !> = 'C': apply Q**H (Conjugate transpose) !>
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. !>
A
!> A is COMPLEX array, dimension !> (LDA,M) if SIDE = 'L', !> (LDA,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 !> CGELQF in the first k rows of its array argument A. !> A is modified by the routine but restored on exit. !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,K). !>
TAU
!> TAU is COMPLEX array, dimension (K) !> TAU(i) must contain the scalar factor of the elementary !> reflector H(i), as returned by CGELQF. !>
C
!> C is COMPLEX array, dimension (LDC,N) !> On entry, the m-by-n matrix C. !> On exit, C is overwritten by Q*C or Q**H*C or 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, dimension !> (N) if SIDE = 'L', !> (M) 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 157 of file cunml2.f.
Releases
4 releases since Debian 7 (Wheezy); the text changed 3 times.