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/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dppt01.f(3) Library Functions Manual /home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dppt01.f(3)

NAME

/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dppt01.f

SYNOPSIS

Functions/Subroutines


subroutine DPPT01 (uplo, n, a, afac, rwork, resid)
DPPT01

Function/Subroutine Documentation

subroutine DPPT01 (character uplo, integer n, double precision, dimension( * ) a, double precision, dimension( * ) afac, double precision, dimension( * ) rwork, double precision resid)

DPPT01

Purpose:

!>
!> DPPT01 reconstructs a symmetric positive definite packed matrix A
!> from its L*L' or U'*U factorization and computes the residual
!>    norm( L*L' - A ) / ( N * norm(A) * EPS ) or
!>    norm( U'*U - A ) / ( N * norm(A) * EPS ),
!> where 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 (N*(N+1)/2)
!>          The original symmetric matrix A, stored as a packed
!>          triangular matrix.
!> 

AFAC

!>          AFAC is DOUBLE PRECISION array, dimension (N*(N+1)/2)
!>          On entry, the factor L or U from the L*L' or U'*U
!>          factorization of A, stored as a packed triangular matrix.
!>          Overwritten with the reconstructed matrix, and then with the
!>          difference L*L' - A (or U'*U - A).
!> 

RWORK

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

RESID

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

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 92 of file dppt01.f.

Author

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Version 3.12.0 LAPACK