1CPOCON(1)                LAPACK routine (version 3.1)                CPOCON(1)
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NAME

6       CPOCON  -  the  reciprocal of the condition number (in the 1-norm) of a
7       complex Hermitian positive definite matrix using the  Cholesky  factor‐
8       ization A = U**H*U or A = L*L**H computed by CPOTRF
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SYNOPSIS

11       SUBROUTINE CPOCON( UPLO, N, A, LDA, ANORM, RCOND, WORK, RWORK, INFO )
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13           CHARACTER      UPLO
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15           INTEGER        INFO, LDA, N
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17           REAL           ANORM, RCOND
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19           REAL           RWORK( * )
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21           COMPLEX        A( LDA, * ), WORK( * )
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PURPOSE

24       CPOCON estimates the reciprocal of the condition number (in the 1-norm)
25       of a complex Hermitian positive definite matrix using the Cholesky fac‐
26       torization A = U**H*U or A = L*L**H computed by CPOTRF.
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28       An  estimate  is  obtained  for norm(inv(A)), and the reciprocal of the
29       condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
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ARGUMENTS

33       UPLO    (input) CHARACTER*1
34               = 'U':  Upper triangle of A is stored;
35               = 'L':  Lower triangle of A is stored.
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37       N       (input) INTEGER
38               The order of the matrix A.  N >= 0.
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40       A       (input) COMPLEX array, dimension (LDA,N)
41               The triangular factor U or L from the Cholesky factorization  A
42               = U**H*U or A = L*L**H, as computed by CPOTRF.
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44       LDA     (input) INTEGER
45               The leading dimension of the array A.  LDA >= max(1,N).
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47       ANORM   (input) REAL
48               The 1-norm (or infinity-norm) of the Hermitian matrix A.
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50       RCOND   (output) REAL
51               The  reciprocal  of  the condition number of the matrix A, com‐
52               puted as RCOND = 1/(ANORM * AINVNM), where AINVNM is  an  esti‐
53               mate of the 1-norm of inv(A) computed in this routine.
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55       WORK    (workspace) COMPLEX array, dimension (2*N)
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57       RWORK   (workspace) REAL array, dimension (N)
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59       INFO    (output) INTEGER
60               = 0:  successful exit
61               < 0:  if INFO = -i, the i-th argument had an illegal value
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65 LAPACK routine (version 3.1)    November 2006                       CPOCON(1)
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