checon_rook (3) Linux Manual Page

checon_rook.f –

Synopsis

Functions/Subroutines

subroutine checon_rook (UPLO, N, A, LDA, IPIV, ANORM, RCOND, WORK, INFO)
CHECON_ROOK estimates the reciprocal of the condition number fort HE matrices using factorization obtained with one of the bounded diagonal pivoting methods (max 2 interchanges)

Function/Subroutine Documentation

subroutine checon_rook (characterUPLO, integerN, complex, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, realANORM, realRCOND, complex, dimension( * )WORK, integerINFO)

CHECON_ROOK estimates the reciprocal of the condition number fort HE matrices using factorization obtained with one of the bounded diagonal pivoting methods (max 2 interchanges)

Purpose:

 CHECON_ROOK estimates the reciprocal of the condition number of a complex

 Hermitian matrix A using the factorization A = U*D*U**H or

 A = L*D*L**H computed by CHETRF_ROOK.

 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:

UPLO

 UPLO is CHARACTER*1

 Specifies whether the details of the factorization are stored

 as an upper or lower triangular matrix.

 = ‘U’: Upper triangular, form is A = U*D*U**H;

 = ‘L’: Lower triangular, form is A = L*D*L**H.

N

 N is INTEGER

 The order of the matrix A. N >= 0.

A

 A is COMPLEX array, dimension (LDA,N)

 The block diagonal matrix D and the multipliers used to

 obtain the factor U or L as computed by CHETRF_ROOK.

LDA

 LDA is INTEGER

 The leading dimension of the array A. LDA >= max(1,N).

IPIV

 IPIV is INTEGER array, dimension (N)

 Details of the interchanges and the block structure of D

 as determined by CHETRF_ROOK.

ANORM

 ANORM is REAL

 The 1-norm of the original matrix A.

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.

WORK

 WORK is COMPLEX 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 2013

Contributors:

November 2013, Igor Kozachenko, Computer Science Division, University of California, Berkeley

September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester

Definition at line 139 of file checon_rook.f.

Author

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