cupgtr()

subroutine cupgtr	(	character	uplo,
		integer	n,
		complex, dimension( * )	ap,
		complex, dimension( * )	tau,
		complex, dimension( ldq, * )	q,
		integer	ldq,
		complex, dimension( * )	work,
		integer	info )

CUPGTR

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Purpose:

!>
!> CUPGTR generates a complex unitary matrix Q which is defined as the
!> product of n-1 elementary reflectors H(i) of order n, as returned by
!> CHPTRD using packed storage:
!>
!> if UPLO = 'U', Q = H(n-1) . . . H(2) H(1),
!>
!> if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).
!> 

Parameters

[in]	UPLO	!> UPLO is CHARACTER*1 !> = 'U': Upper triangular packed storage used in previous !> call to CHPTRD; !> = 'L': Lower triangular packed storage used in previous !> call to CHPTRD. !>
[in]	N	!> N is INTEGER !> The order of the matrix Q. N >= 0. !>
[in]	AP	!> AP is COMPLEX array, dimension (N*(N+1)/2) !> The vectors which define the elementary reflectors, as !> returned by CHPTRD. !>
[in]	TAU	!> TAU is COMPLEX array, dimension (N-1) !> TAU(i) must contain the scalar factor of the elementary !> reflector H(i), as returned by CHPTRD. !>
[out]	Q	!> Q is COMPLEX array, dimension (LDQ,N) !> The N-by-N unitary matrix Q. !>
[in]	LDQ	!> LDQ is INTEGER !> The leading dimension of the array Q. LDQ >= max(1,N). !>
[out]	WORK	!> WORK is COMPLEX array, dimension (N-1) !>
[out]	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.