1ZUNG2R(1)                LAPACK routine (version 3.2)                ZUNG2R(1)
2
3
4

NAME

6       ZUNG2R - generates an m by n complex matrix Q with orthonormal columns,
7

SYNOPSIS

9       SUBROUTINE ZUNG2R( M, N, K, A, LDA, TAU, WORK, INFO )
10
11           INTEGER        INFO, K, LDA, M, N
12
13           COMPLEX*16     A( LDA, * ), TAU( * ), WORK( * )
14

PURPOSE

16       ZUNG2R  generates  an m by n complex matrix Q with orthonormal columns,
17       which is defined as the first n columns of a product  of  k  elementary
18       reflectors of order m
19             Q  =  H(1) H(2) . . . H(k)
20       as returned by ZGEQRF.
21

ARGUMENTS

23       M       (input) INTEGER
24               The number of rows of the matrix Q. M >= 0.
25
26       N       (input) INTEGER
27               The number of columns of the matrix Q. M >= N >= 0.
28
29       K       (input) INTEGER
30               The  number  of elementary reflectors whose product defines the
31               matrix Q. N >= K >= 0.
32
33       A       (input/output) COMPLEX*16 array, dimension (LDA,N)
34               On entry, the i-th column must contain the vector which defines
35               the  elementary  reflector H(i), for i = 1,2,...,k, as returned
36               by ZGEQRF in the first k columns of its array argument  A.   On
37               exit, the m by n matrix Q.
38
39       LDA     (input) INTEGER
40               The first dimension of the array A. LDA >= max(1,M).
41
42       TAU     (input) COMPLEX*16 array, dimension (K)
43               TAU(i) must contain the scalar factor of the elementary reflec‐
44               tor H(i), as returned by ZGEQRF.
45
46       WORK    (workspace) COMPLEX*16 array, dimension (N)
47
48       INFO    (output) INTEGER
49               = 0: successful exit
50               < 0: if INFO = -i, the i-th argument has an illegal value
51
52
53
54 LAPACK routine (version 3.2)    November 2008                       ZUNG2R(1)