zungl2.f man page

zungl2.f —

Synopsis

Functions/Subroutines

subroutine zungl2 (M, N, K, A, LDA, TAU, WORK, INFO)
ZUNGL2 generates all or part of the unitary matrix Q from an LQ factorization determined by cgelqf (unblocked algorithm).

Function/Subroutine Documentation

subroutine zungl2 (integerM, integerN, integerK, complex*16, dimension( lda, * )A, integerLDA, complex*16, dimension( * )TAU, complex*16, dimension( * )WORK, integerINFO)

ZUNGL2 generates all or part of the unitary matrix Q from an LQ factorization determined by cgelqf (unblocked algorithm).

Purpose:

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.

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*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.

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 ZGELQF.

WORK

WORK is COMPLEX*16 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.

Date:

September 2012

Definition at line 114 of file zungl2.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

zungl2(3) is an alias of zungl2.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK