dppt03.f3

Usage

Functions/Subroutines

subroutine dppt03 (uplo, n, a, ainv, work, ldwork, rwork, rcond, resid)
DPPT03

Function/Subroutine Documentation

subroutine dppt03 (character uplo, integer n, double precision, dimension( * ) a, double precision, dimension( * ) ainv, double precision, dimension( ldwork, * ) work, integer ldwork, double precision, dimension( * ) rwork, double precision rcond, double precision resid)

DPPT03

Purpose:

!>
!> DPPT03 computes the residual for a symmetric packed matrix times its
!> inverse:
!>    norm( I - A*AINV ) / ( N * norm(A) * norm(AINV) * 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 is INTEGER
!>          The number of rows and columns of the matrix A.  N >= 0.
!>

!>          A is DOUBLE PRECISION array, dimension (N*(N+1)/2)
!>          The original symmetric matrix A, stored as a packed
!>          triangular matrix.
!>

AINV

!>          AINV is DOUBLE PRECISION array, dimension (N*(N+1)/2)
!>          The (symmetric) inverse of the matrix A, stored as a packed
!>          triangular matrix.
!>

WORK

!>          WORK is DOUBLE PRECISION array, dimension (LDWORK,N)
!>

LDWORK

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

RWORK

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

RCOND

!>          RCOND is DOUBLE PRECISION
!>          The reciprocal of the condition number of A, computed as
!>          ( 1/norm(A) ) / norm(AINV).
!>

RESID

!>          RESID is DOUBLE PRECISION
!>          norm(I - A*AINV) / ( N * norm(A) * norm(AINV) * EPS )
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 108 of file dppt03.f.