
chetri2.f(3) LAPACK chetri2.f(3)
NAME
chetri2.f 
SYNOPSIS
Functions/Subroutines
subroutine chetri2 (UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO)
CHETRI2
Function/Subroutine Documentation
subroutine chetri2 (characterUPLO, integerN, complex, dimension( lda, * )A, integerLDA,
integer, dimension( * )IPIV, complex, dimension( * )WORK, integerLWORK, integerINFO)
CHETRI2
Purpose:
CHETRI2 computes the inverse of a COMPLEX hermitian indefinite matrix
A using the factorization A = U*D*U**T or A = L*D*L**T computed by
CHETRF. CHETRI2 set the LEADING DIMENSION of the workspace
before calling CHETRI2X that actually computes the inverse.
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**T;
= 'L': Lower triangular, form is A = L*D*L**T.
N
N is INTEGER
The order of the matrix A. N >= 0.
A
A is COMPLEX array, dimension (LDA,N)
On entry, the NB diagonal matrix D and the multipliers
used to obtain the factor U or L as computed by CHETRF.
On exit, if INFO = 0, the (symmetric) 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 NB structure of D
as determined by CHETRF.
WORK
WORK is COMPLEX array, dimension (N+NB+1)*(NB+3)
LWORK
LWORK is INTEGER
The dimension of the array WORK.
WORK is size >= (N+NB+1)*(NB+3)
If LDWORK = 1, then a workspace query is assumed; the routine
calculates:
 the optimal size of the WORK array, returns
this value as the first entry of the WORK array,
 and no error message related to LDWORK is issued by XERBLA.
INFO
INFO is 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.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011
Definition at line 128 of file chetri2.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 chetri2.f(3) 
