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/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/cungl2.f(3) Library Functions Manual /home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/cungl2.f(3)

NAME

/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/cungl2.f

SYNOPSIS

Functions/Subroutines


subroutine CUNGL2 (m, n, k, a, lda, tau, work, info)
CUNGL2 generates all or part of the unitary matrix Q from an LQ factorization determined by cgelqf (unblocked algorithm).

Function/Subroutine Documentation

subroutine CUNGL2 (integer m, integer n, integer k, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) tau, complex, dimension( * ) work, integer info)

CUNGL2 generates all or part of the unitary matrix Q from an LQ factorization determined by cgelqf (unblocked algorithm).

Purpose:

!>
!> CUNGL2 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 CGELQF.
!>

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 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 CGELQF 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 array, dimension (K)
!>          TAU(i) must contain the scalar factor of the elementary
!>          reflector H(i), as returned by CGELQF.
!>

WORK

!>          WORK is COMPLEX 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 cungl2.f.

Author

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Version 3.12.0 LAPACK