csytri2x.f man page

csytri2x.f

Synopsis

Functions/Subroutines

subroutine csytri2x (UPLO, N, A, LDA, IPIV, WORK, NB, INFO)
CSYTRI2X

Function/Subroutine Documentation

subroutine csytri2x (character UPLO, integer N, complex, dimension( lda, * ) A, integer LDA, integer, dimension( * ) IPIV, complex, dimension( n+nb+1,* ) WORK, integer NB, integer INFO)

CSYTRI2X  

Purpose:

 CSYTRI2X 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
 CSYTRF.
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 NNB diagonal matrix D and the multipliers
          used to obtain the factor U or L as computed by CSYTRF.

          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 CSYTRF.

WORK

          WORK is COMPLEX 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 csytri2x.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page csytri2x(3) is an alias of csytri2x.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK