ssytri2x.f man page

ssytri2x.f —

Synopsis

Functions/Subroutines

subroutine ssytri2x (UPLO, N, A, LDA, IPIV, WORK, NB, INFO)
SSYTRI2X

Function/Subroutine Documentation

subroutine ssytri2x (character UPLO, integer N, real, dimension( lda, * ) A, integer LDA, integer, dimension( * ) IPIV, real, dimension( n+nb+1,* ) WORK, integer NB, integer INFO)

SSYTRI2X  

Purpose:

 SSYTRI2X 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
 SSYTRF.
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 REAL 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 SSYTRF.

          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 SSYTRF.

WORK

          WORK is REAL array, dimension (N+NB+1,NB+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:

June 2017

Definition at line 122 of file ssytri2x.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page ssytri2x(3) is an alias of ssytri2x.f(3).

Sat Jun 24 2017 Version 3.7.1 LAPACK