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/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/ssyt01_3.f(3) Library Functions Manual /home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/ssyt01_3.f(3)

NAME

/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/ssyt01_3.f

SYNOPSIS

Functions/Subroutines


subroutine SSYT01_3 (uplo, n, a, lda, afac, ldafac, e, ipiv, c, ldc, rwork, resid)
SSYT01_3

Function/Subroutine Documentation

subroutine SSYT01_3 (character uplo, integer n, real, dimension( lda, * ) a, integer lda, real, dimension( ldafac, * ) afac, integer ldafac, real, dimension( * ) e, integer, dimension( * ) ipiv, real, dimension( ldc, * ) c, integer ldc, real, dimension( * ) rwork, real resid)

SSYT01_3

Purpose:

!>
!> SSYT01_3 reconstructs a symmetric indefinite matrix A from its
!> block L*D*L' or U*D*U' factorization computed by SSYTRF_RK
!> (or SSYTRF_BK) and computes the residual
!>    norm( C - A ) / ( N * norm(A) * EPS ),
!> where C is the reconstructed matrix and EPS is the machine epsilon.
!> 

Parameters

UPLO

!>          UPLO is CHARACTER*1
!>          Specifies whether the upper or lower triangular part of the
!>          symmetric matrix A is stored:
!>          = 'U':  Upper triangular
!>          = 'L':  Lower triangular
!> 

N

!>          N is INTEGER
!>          The number of rows and columns of the matrix A.  N >= 0.
!> 

A

!>          A is DOUBLE PRECISION array, dimension (LDA,N)
!>          The original symmetric matrix A.
!> 

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N)
!> 

AFAC

!>          AFAC is DOUBLE PRECISION array, dimension (LDAFAC,N)
!>          Diagonal of the block diagonal matrix D and factors U or L
!>          as computed by SSYTRF_RK and SSYTRF_BK:
!>            a) ONLY diagonal elements of the symmetric block diagonal
!>               matrix D on the diagonal of A, i.e. D(k,k) = A(k,k);
!>               (superdiagonal (or subdiagonal) elements of D
!>                should be provided on entry in array E), and
!>            b) If UPLO = 'U': factor U in the superdiagonal part of A.
!>               If UPLO = 'L': factor L in the subdiagonal part of A.
!> 

LDAFAC

!>          LDAFAC is INTEGER
!>          The leading dimension of the array AFAC.
!>          LDAFAC >= max(1,N).
!> 

E

!>          E is DOUBLE PRECISION array, dimension (N)
!>          On entry, contains the superdiagonal (or subdiagonal)
!>          elements of the symmetric block diagonal matrix D
!>          with 1-by-1 or 2-by-2 diagonal blocks, where
!>          If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced;
!>          If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
!> 

IPIV

!>          IPIV is INTEGER array, dimension (N)
!>          The pivot indices from SSYTRF_RK (or SSYTRF_BK).
!> 

C

!>          C is DOUBLE PRECISION array, dimension (LDC,N)
!> 

LDC

!>          LDC is INTEGER
!>          The leading dimension of the array C.  LDC >= max(1,N).
!> 

RWORK

!>          RWORK is DOUBLE PRECISION array, dimension (N)
!> 

RESID

!>          RESID is DOUBLE PRECISION
!>          If UPLO = 'L', norm(L*D*L' - A) / ( N * norm(A) * EPS )
!>          If UPLO = 'U', norm(U*D*U' - A) / ( N * norm(A) * EPS )
!> 

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 138 of file ssyt01_3.f.

Author

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Version 3.12.0 LAPACK