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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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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).
Download ZUNGL2 + dependencies [TGZ] [ZIP] [TXT]
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.
[in] | M | M is INTEGER The number of rows of the matrix Q. M >= 0. |
[in] | N | N is INTEGER The number of columns of the matrix Q. N >= M. |
[in] | K | K is INTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0. |
[in,out] | 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. |
[in] | LDA | LDA is INTEGER The first dimension of the array A. LDA >= max(1,M). |
[in] | 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. |
[out] | WORK | WORK is COMPLEX*16 array, dimension (M) |
[out] | INFO | INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value |
Definition at line 115 of file zungl2.f.