csytri2.f

Section: LAPACK (3)
Updated: Tue Nov 14 2017
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NAME

csytri2.f  

SYNOPSIS


 

Functions/Subroutines


subroutine csytri2 (UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO)
CSYTRI2  

Function/Subroutine Documentation

 

subroutine csytri2 (character UPLO, integer N, complex, dimension( lda, * ) A, integer LDA, integer, dimension( * ) IPIV, complex, dimension( * ) WORK, integer LWORK, integer INFO)

CSYTRI2

Purpose:

 CSYTRI2 computes the inverse of a COMPLEX symmetric indefinite matrix
 A using the factorization A = U*D*U**T or A = L*D*L**T computed by
 CSYTRF. CSYTRI2 sets the LEADING DIMENSION of the workspace
 before calling CSYTRI2X 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 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 NB structure of D
          as determined by CSYTRF.


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 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 2017

Definition at line 129 of file csytri2.f.  

Author

Generated automatically by Doxygen for LAPACK from the source code.


 

Index

NAME
SYNOPSIS
Functions/Subroutines
Function/Subroutine Documentation
subroutine csytri2 (character UPLO, integer N, complex, dimension( lda, * ) A, integer LDA, integer, dimension( * ) IPIV, complex, dimension( * ) WORK, integer LWORK, integer INFO)
Author
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