chetri_rook (3) Linux Manual Page

chetri_rook.f –

Synopsis

Functions/Subroutines

subroutine chetri_rook (UPLO, N, A, LDA, IPIV, WORK, INFO)
CHETRI_ROOK computes the inverse of HE matrix using the factorization obtained with the bounded Bunch-Kaufman (‘rook’) diagonal pivoting method.

Function/Subroutine Documentation

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

CHETRI_ROOK computes the inverse of HE matrix using the factorization obtained with the bounded Bunch-Kaufman (‘rook’) diagonal pivoting method.

Purpose:

 CHETRI_ROOK computes the inverse of a complex Hermitian indefinite matrix

 A using the factorization A = U*D*U**H or A = L*D*L**H computed by

 CHETRF_ROOK.

 

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)

 On entry, the block diagonal matrix D and the multipliers

 used to obtain the factor U or L as computed by CHETRF_ROOK.

 On exit, if INFO = 0, the (Hermitian) inverse of the original

 matrix. If UPLO = ‘U’, the upper triangular part of the

 inverse is formed and the part of A below the diagonal is not

 referenced; if UPLO = ‘L’ the lower triangular part of the

 inverse is formed and the part of A above the diagonal is

 not referenced.

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.

WORK

 WORK is COMPLEX array, dimension (N)

INFO

 INFO is INTEGER

 = 0: successful exit

 < 0: if INFO = -i, the i-th argument had an illegal value

 > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its

 inverse could not be computed.

 

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 129 of file chetri_rook.f.

Author

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