CUNG2R(l) ) CUNG2R(l)NAME
CUNG2R - generate an m by n complex matrix Q with orthonormal columns,
SYNOPSIS
SUBROUTINE CUNG2R( M, N, K, A, LDA, TAU, WORK, INFO )
INTEGER INFO, K, LDA, M, N
COMPLEX A( LDA, * ), TAU( * ), WORK( * )
PURPOSE
CUNG2R generates an m by n complex matrix Q with orthonormal columns,
which is defined as the first n columns of a product of k elementary
reflectors of order m
Q = H(1)H(2) . . . H(k)
as returned by CGEQRF.
ARGUMENTS
M (input) INTEGER
The number of rows of the matrix Q. M >= 0.
N (input) INTEGER
The number of columns of the matrix Q. M >= N >= 0.
K (input) INTEGER
The number of elementary reflectors whose product defines the
matrix Q. N >= K >= 0.
A (input/output) COMPLEX array, dimension (LDA,N)
On entry, the i-th column must contain the vector which defines
the elementary reflector H(i), for i = 1,2,...,k, as returned
by CGEQRF in the first k columns of its array argument A. On
exit, the m by n matrix Q.
LDA (input) INTEGER
The first dimension of the array A. LDA >= max(1,M).
TAU (input) COMPLEX array, dimension (K)
TAU(i) must contain the scalar factor of the elementary reflec‐
tor H(i), as returned by CGEQRF.
WORK (workspace) COMPLEX array, dimension (N)
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an illegal value
LAPACK version 3.0 15 June 2000 CUNG2R(l)
