zunglq()

subroutine zunglq	(	integer	m,
		integer	n,
		integer	k,
		complex*16, dimension( lda, * )	a,
		integer	lda,
		complex*16, dimension( * )	tau,
		complex*16, dimension( * )	work,
		integer	lwork,
		integer	info )

ZUNGLQ

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Purpose:

!>
!> ZUNGLQ 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

[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 (MAX(1,LWORK)) !> On exit, if INFO = 0, WORK(1) returns the optimal LWORK. !>
[in]	LWORK	!> LWORK is INTEGER !> The dimension of the array WORK. LWORK >= max(1,M). !> For optimum performance LWORK >= M*NB, where NB is !> the optimal blocksize. !> !> If LWORK = -1, then a workspace query is assumed; the routine !> only calculates the optimal size of the WORK array, returns !> this value as the first entry of the WORK array, and no error !> message related to LWORK is issued by XERBLA. !>
[out]	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.