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cgecon.f(3) LAPACK cgecon.f(3)

NAME

cgecon.f -

SYNOPSIS

Functions/Subroutines


subroutine cgecon (NORM, N, A, LDA, ANORM, RCOND, WORK, RWORK, INFO)
 
CGECON

Function/Subroutine Documentation

subroutine cgecon (characterNORM, integerN, complex, dimension( lda, * )A, integerLDA, realANORM, realRCOND, complex, dimension( * )WORK, real, dimension( * )RWORK, integerINFO)

CGECON
Purpose:
 CGECON estimates the reciprocal of the condition number of a general
 complex matrix A, in either the 1-norm or the infinity-norm, using
 the LU factorization computed by CGETRF.
An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / ( norm(A) * norm(inv(A)) ).
Parameters:
NORM
          NORM is CHARACTER*1
          Specifies whether the 1-norm condition number or the
          infinity-norm condition number is required:
          = '1' or 'O':  1-norm;
          = 'I':         Infinity-norm.
N
          N is INTEGER
          The order of the matrix A.  N >= 0.
A
          A is COMPLEX array, dimension (LDA,N)
          The factors L and U from the factorization A = P*L*U
          as computed by CGETRF.
LDA
          LDA is INTEGER
          The leading dimension of the array A.  LDA >= max(1,N).
ANORM
          ANORM is REAL
          If NORM = '1' or 'O', the 1-norm of the original matrix A.
          If NORM = 'I', the infinity-norm of the original matrix A.
RCOND
          RCOND is REAL
          The reciprocal of the condition number of the matrix A,
          computed as RCOND = 1/(norm(A) * norm(inv(A))).
WORK
          WORK is COMPLEX array, dimension (2*N)
RWORK
          RWORK is REAL array, dimension (2*N)
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 124 of file cgecon.f.

Author

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