LAPACK  3.4.0
LAPACK: Linear Algebra PACKage
Functions/Subroutines
cppcon.f File Reference

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Functions/Subroutines

subroutine CPPCON (UPLO, N, AP, ANORM, RCOND, WORK, RWORK, INFO)
 CPPCON

Function/Subroutine Documentation

subroutine CPPCON ( CHARACTER  UPLO,
INTEGER  N,
COMPLEX, dimension( * )  AP,
REAL  ANORM,
REAL  RCOND,
COMPLEX, dimension( * )  WORK,
REAL, dimension( * )  RWORK,
INTEGER  INFO 
)

CPPCON

Download CPPCON + dependencies [TGZ] [ZIP] [TXT]
Purpose: 

 CPPCON estimates the reciprocal of the condition number (in the 
 1-norm) of a complex Hermitian positive definite packed matrix using
 the Cholesky factorization A = U**H*U or A = L*L**H computed by
 CPPTRF.

 An estimate is obtained for norm(inv(A)), and the reciprocal of the
 condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
Parameters:
[in]UPLO
          UPLO is CHARACTER*1
          = 'U':  Upper triangle of A is stored;
          = 'L':  Lower triangle of A is stored.
[in]N
          N is INTEGER
          The order of the matrix A.  N >= 0.
[in]AP
          AP is COMPLEX array, dimension (N*(N+1)/2)
          The triangular factor U or L from the Cholesky factorization
          A = U**H*U or A = L*L**H, packed columnwise in a linear
          array.  The j-th column of U or L is stored in the array AP
          as follows:
          if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;
          if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.
[in]ANORM
          ANORM is REAL
          The 1-norm (or infinity-norm) of the Hermitian matrix A.
[out]RCOND
          RCOND is REAL
          The reciprocal of the condition number of the matrix A,
          computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an
          estimate of the 1-norm of inv(A) computed in this routine.
[out]WORK
          WORK is COMPLEX array, dimension (2*N)
[out]RWORK
          RWORK is REAL array, dimension (N)
[out]INFO
          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011

Definition at line 119 of file cppcon.f.

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