dppt03.f - Man Page

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

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

          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.

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.