chetri (l)  Linux Man Pages
chetri: 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
Command to display chetri
manual in Linux: $ man l chetri
NAME
CHETRI  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
SYNOPSIS
 SUBROUTINE CHETRI(

UPLO, N, A, LDA, IPIV, WORK, INFO )

CHARACTER
UPLO

INTEGER
INFO, LDA, N

INTEGER
IPIV( * )

COMPLEX
A( LDA, * ), WORK( * )
PURPOSE
CHETRI 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.
ARGUMENTS
 UPLO (input) CHARACTER*1

Specifies whether the details of the factorization are stored
as an upper or lower triangular matrix.
= aqUaq: Upper triangular, form is A = U*D*U**H;
= aqLaq: Lower triangular, form is A = L*D*L**H.
 N (input) INTEGER

The order of the matrix A. N >= 0.
 A (input/output) 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.
On exit, if INFO = 0, the (Hermitian) inverse of the original
matrix. If UPLO = aqUaq, the upper triangular part of the
inverse is formed and the part of A below the diagonal is not
referenced; if UPLO = aqLaq the lower triangular part of the
inverse is formed and the part of A above the diagonal is
not referenced.
 LDA (input) INTEGER

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

Details of the interchanges and the block structure of D
as determined by CHETRF.
 WORK (workspace) COMPLEX array, dimension (N)

 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
> 0: if INFO = i, D(i,i) = 0; the matrix is singular and its
inverse could not be computed.
Pages related to chetri
 chetri (3)
 chetrd (l)  reduces a complex Hermitian matrix A to real symmetric tridiagonal form T by a unitary similarity transformation
 chetrf (l)  computes the factorization of a complex Hermitian matrix A using the BunchKaufman diagonal pivoting method
 chetrs (l)  solves a system of linear equations A*X = B with a complex Hermitian matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by CHETRF
 chetd2 (l)  reduces a complex Hermitian matrix A to real symmetric tridiagonal form T by a unitary similarity transformation
 chetf2 (l)  computes the factorization of a complex Hermitian matrix A using the BunchKaufman diagonal pivoting method
 checon (l)  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
 cheequb (l)  computes row and column scalings intended to equilibrate a symmetric matrix A and reduce its condition number (with respect to the twonorm)