1ZUNGR2(1) LAPACK routine (version 3.2) ZUNGR2(1)
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6 ZUNGR2 - generates an m by n complex matrix Q with orthonormal rows,
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9 SUBROUTINE ZUNGR2( M, N, K, A, LDA, TAU, WORK, INFO )
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11 INTEGER INFO, K, LDA, M, N
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13 COMPLEX*16 A( LDA, * ), TAU( * ), WORK( * )
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16 ZUNGR2 generates an m by n complex matrix Q with orthonormal rows,
17 which is defined as the last m rows of a product of k elementary
18 reflectors of order n
19 Q = H(1)' H(2)' . . . H(k)'
20 as returned by ZGERQF.
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23 M (input) INTEGER
24 The number of rows of the matrix Q. M >= 0.
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26 N (input) INTEGER
27 The number of columns of the matrix Q. N >= M.
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29 K (input) INTEGER
30 The number of elementary reflectors whose product defines the
31 matrix Q. M >= K >= 0.
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33 A (input/output) COMPLEX*16 array, dimension (LDA,N)
34 On entry, the (m-k+i)-th row must contain the vector which
35 defines the elementary reflector H(i), for i = 1,2,...,k, as
36 returned by ZGERQF in the last k rows of its array argument A.
37 On exit, the m-by-n matrix Q.
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39 LDA (input) INTEGER
40 The first dimension of the array A. LDA >= max(1,M).
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42 TAU (input) COMPLEX*16 array, dimension (K)
43 TAU(i) must contain the scalar factor of the elementary reflecā
44 tor H(i), as returned by ZGERQF.
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46 WORK (workspace) COMPLEX*16 array, dimension (M)
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48 INFO (output) INTEGER
49 = 0: successful exit
50 < 0: if INFO = -i, the i-th argument has an illegal value
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54 LAPACK routine (version 3.2) November 2008 ZUNGR2(1)