chptri (l)  Linux Manuals
chptri: computes the inverse of a complex Hermitian indefinite matrix A in packed storage using the factorization A = U*D*U**H or A = L*D*L**H computed by CHPTRF
Command to display chptri
manual in Linux: $ man l chptri
NAME
CHPTRI  computes the inverse of a complex Hermitian indefinite matrix A in packed storage using the factorization A = U*D*U**H or A = L*D*L**H computed by CHPTRF
SYNOPSIS
 SUBROUTINE CHPTRI(

UPLO, N, AP, IPIV, WORK, INFO )

CHARACTER
UPLO

INTEGER
INFO, N

INTEGER
IPIV( * )

COMPLEX
AP( * ), WORK( * )
PURPOSE
CHPTRI computes the inverse of a complex Hermitian indefinite matrix
A in packed storage using the factorization A = U*D*U**H or
A = L*D*L**H computed by CHPTRF.
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.
 AP (input/output) COMPLEX array, dimension (N*(N+1)/2)

On entry, the block diagonal matrix D and the multipliers
used to obtain the factor U or L as computed by CHPTRF,
stored as a packed triangular matrix.
On exit, if INFO = 0, the (Hermitian) inverse of the original
matrix, stored as a packed triangular matrix. The jth column
of inv(A) is stored in the array AP as follows:
if UPLO = aqUaq, AP(i + (j1)*j/2) = inv(A)(i,j) for 1<=i<=j;
if UPLO = aqLaq,
AP(i + (j1)*(2nj)/2) = inv(A)(i,j) for j<=i<=n.
 IPIV (input) INTEGER array, dimension (N)

Details of the interchanges and the block structure of D
as determined by CHPTRF.
 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 chptri
 chptri (3)
 chptrd (l)  reduces a complex Hermitian matrix A stored in packed form to real symmetric tridiagonal form T by a unitary similarity transformation
 chptrf (l)  computes the factorization of a complex Hermitian packed matrix A using the BunchKaufman diagonal pivoting method
 chptrs (l)  solves a system of linear equations A*X = B with a complex Hermitian matrix A stored in packed format using the factorization A = U*D*U**H or A = L*D*L**H computed by CHPTRF
 chpcon (l)  estimates the reciprocal of the condition number of a complex Hermitian packed matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by CHPTRF
 chpev (l)  computes all the eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix in packed storage
 chpevd (l)  computes all the eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A in packed storage
 chpevx (l)  computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A in packed storage