dsytri2x.f (3)  Linux Man Pages
NAME
dsytri2x.f 
SYNOPSIS
Functions/Subroutines
subroutine dsytri2x (UPLO, N, A, LDA, IPIV, WORK, NB, INFO)
DSYTRI2X
Function/Subroutine Documentation
subroutine dsytri2x (characterUPLO, integerN, double precision, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, double precision, dimension( n+nb+1,* )WORK, integerNB, integerINFO)
DSYTRI2X
Purpose:

DSYTRI2X computes the inverse of a real symmetric indefinite matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by DSYTRF.
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.
NN is INTEGER The order of the matrix A. N >= 0.
AA is DOUBLE PRECISION array, dimension (LDA,N) On entry, the NNB diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSYTRF. 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.
LDALDA is INTEGER The leading dimension of the array A. LDA >= max(1,N).
IPIVIPIV is INTEGER array, dimension (N) Details of the interchanges and the NNB structure of D as determined by DSYTRF.
WORKWORK is DOUBLE PRECISION array, dimension (N+NNB+1,NNB+3)
NBNB is INTEGER Block size
INFOINFO 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 121 of file dsytri2x.f.
Author
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