dsytri2x.f man page

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.

N

N is INTEGER
The order of the matrix A.  N >= 0.

A

A 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.

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 NNB structure of D
as determined by DSYTRF.

WORK

WORK is DOUBLE PRECISION array, dimension (N+NNB+1,NNB+3)

NB

NB is INTEGER
Block size

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 2011

Definition at line 121 of file dsytri2x.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dsytri2x(3) is an alias of dsytri2x.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK