zungl2.f - Man Page
SRC/zungl2.f
Synopsis
Functions/Subroutines
subroutine zungl2 (m, n, k, a, lda, tau, work, info)
ZUNGL2 generates all or part of the unitary matrix Q from an LQ factorization determined by cgelqf (unblocked algorithm).
Function/Subroutine Documentation
subroutine zungl2 (integer m, integer n, integer k, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) tau, complex*16, dimension( * ) work, integer info)
ZUNGL2 generates all or part of the unitary matrix Q from an LQ factorization determined by cgelqf (unblocked algorithm).
Purpose:
ZUNGL2 generates an m-by-n complex matrix Q with orthonormal rows, which is defined as the first m rows of a product of k elementary reflectors of order n Q = H(k)**H . . . H(2)**H H(1)**H as returned by ZGELQF.
- Parameters
M
M is INTEGER The number of rows of the matrix Q. M >= 0.
N
N is INTEGER The number of columns of the matrix Q. N >= M.
K
K is INTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0.
A
A is COMPLEX*16 array, dimension (LDA,N) On entry, the i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGELQF in the first k rows of its array argument A. On exit, the m by n matrix Q.
LDA
LDA is INTEGER The first dimension of the array A. LDA >= max(1,M).
TAU
TAU is COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGELQF.
WORK
WORK is COMPLEX*16 array, dimension (M)
INFO
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value
- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 112 of file zungl2.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Referenced By
The man page zungl2(3) is an alias of zungl2.f(3).
Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK