subroutine zung2l (M, N, K, A, LDA, TAU, WORK, INFO)
subroutine zung2l (integerM, integerN, integerK, complex*16, dimension( lda, * )A, integerLDA, complex*16, dimension( * )TAU, complex*16, dimension( * )WORK, integerINFO)ZUNG2L generates all or part of the unitary matrix Q from a QL factorization determined by cgeqlf (unblocked algorithm). Purpose:
ZUNG2L generates an m by n complex matrix Q with orthonormal columns, which is defined as the last n columns of a product of k elementary reflectors of order m Q = H(k) . . . H(2) H(1) as returned by ZGEQLF.
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. M >= N >= 0.K
K is INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.A
A is COMPLEX*16 array, dimension (LDA,N) On entry, the (n-k+i)-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGEQLF in the last k columns 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 ZGEQLF.WORK
WORK is COMPLEX*16 array, dimension (N)INFO
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value
Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.Date:
September 2012Definition at line 115 of file zung2l.f.