1CGEQPF(1)       LAPACK deprecated driver routine (version 3.1)       CGEQPF(1)
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NAME

6       CGEQPF - i deprecated and has been replaced by routine CGEQP3
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SYNOPSIS

9       SUBROUTINE CGEQPF( M, N, A, LDA, JPVT, TAU, WORK, RWORK, INFO )
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11           INTEGER        INFO, LDA, M, N
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13           INTEGER        JPVT( * )
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15           REAL           RWORK( * )
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17           COMPLEX        A( LDA, * ), TAU( * ), WORK( * )
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PURPOSE

20       This routine is deprecated and has been replaced by routine CGEQP3.
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22       CGEQPF computes a QR factorization with column pivoting of a complex M-
23       by-N matrix A: A*P = Q*R.
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ARGUMENTS

27       M       (input) INTEGER
28               The number of rows of the matrix A. M >= 0.
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30       N       (input) INTEGER
31               The number of columns of the matrix A. N >= 0
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33       A       (input/output) COMPLEX array, dimension (LDA,N)
34               On entry, the M-by-N matrix A.  On exit, the upper triangle  of
35               the array contains the min(M,N)-by-N upper triangular matrix R;
36               the elements below the diagonal, together with the  array  TAU,
37               represent the unitary matrix Q as a product of min(m,n) elemen‐
38               tary reflectors.
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40       LDA     (input) INTEGER
41               The leading dimension of the array A. LDA >= max(1,M).
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43       JPVT    (input/output) INTEGER array, dimension (N)
44               On entry, if JPVT(i) .ne. 0, the i-th column of A  is  permuted
45               to  the front of A*P (a leading column); if JPVT(i) = 0, the i-
46               th column of A is a free column.  On exit, if JPVT(i) = k, then
47               the i-th column of A*P was the k-th column of A.
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49       TAU     (output) COMPLEX array, dimension (min(M,N))
50               The scalar factors of the elementary reflectors.
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52       WORK    (workspace) COMPLEX array, dimension (N)
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54       RWORK   (workspace) REAL array, dimension (2*N)
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56       INFO    (output) INTEGER
57               = 0:  successful exit
58               < 0:  if INFO = -i, the i-th argument had an illegal value
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FURTHER DETAILS

61       The matrix Q is represented as a product of elementary reflectors
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63          Q = H(1) H(2) . . . H(n)
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65       Each H(i) has the form
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67          H = I - tau * v * v'
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69       where  tau is a complex scalar, and v is a complex vector with v(1:i-1)
70       = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i).
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72       The matrix P is represented in jpvt as follows: If
73          jpvt(j) = i
74       then the jth column of P is the ith canonical unit vector.
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76       Partial column norm updating strategy modified by
77         Z. Drmac and Z. Bujanovic, Dept. of Mathematics,
78         University of Zagreb, Croatia.
79         June 2006.
80       For more details see LAPACK Working Note 176.
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85 LAPACK deprecated driver routineN(ovveermsbieorn230.016)                      CGEQPF(1)