1CUNG2R(1) LAPACK routine (version 3.2) CUNG2R(1)
2
3
4
6 CUNG2R - generates an m by n complex matrix Q with orthonormal columns,
7
9 SUBROUTINE CUNG2R( M, N, K, A, LDA, TAU, WORK, INFO )
10
11 INTEGER INFO, K, LDA, M, N
12
13 COMPLEX A( LDA, * ), TAU( * ), WORK( * )
14
16 CUNG2R 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 CGEQRF.
21
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 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 CGEQRF 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 array, dimension (K)
43 TAU(i) must contain the scalar factor of the elementary reflecā
44 tor H(i), as returned by CGEQRF.
45
46 WORK (workspace) COMPLEX 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 CUNG2R(1)