TESTING/LIN/dtpt01.f(3)    Library Functions Manual    TESTING/LIN/dtpt01.f(3)

NAME
       TESTING/LIN/dtpt01.f

SYNOPSIS
   Functions/Subroutines
       subroutine dtpt01 (uplo, diag, n, ap, ainvp, rcond, work, resid)
           DTPT01

Function/Subroutine Documentation
   subroutine dtpt01 (character uplo, character diag, integer n, double
       precision, dimension( * ) ap, double precision, dimension( * ) ainvp,
       double precision rcond, double precision, dimension( * ) work, double
       precision resid)
       DTPT01

       Purpose:


           !>
           !> DTPT01 computes the residual for a triangular matrix A times its
           !> inverse when A is stored in packed format:
           !>    RESID = norm(A*AINV - I) / ( N * norm(A) * norm(AINV) * EPS ),
           !> where EPS is the machine epsilon.
           !>

       Parameters
           UPLO

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

           DIAG

           !>          DIAG is CHARACTER*1
           !>          Specifies whether or not the matrix A is unit triangular.
           !>          = 'N':  Non-unit triangular
           !>          = 'U':  Unit triangular
           !>

           N

           !>          N is INTEGER
           !>          The order of the matrix A.  N >= 0.
           !>

           AP

           !>          AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)
           !>          The original upper or lower triangular matrix A, packed
           !>          columnwise in a linear array.  The j-th column of A is stored
           !>          in the array AP as follows:
           !>          if UPLO = 'U', AP((j-1)*j/2 + i) = A(i,j) for 1<=i<=j;
           !>          if UPLO = 'L',
           !>             AP((j-1)*(n-j) + j*(j+1)/2 + i-j) = A(i,j) for j<=i<=n.
           !>

           AINVP

           !>          AINVP is DOUBLE PRECISION array, dimension (N*(N+1)/2)
           !>          On entry, the (triangular) inverse of the matrix A, packed
           !>          columnwise in a linear array as in AP.
           !>          On exit, the contents of AINVP are destroyed.
           !>

           RCOND

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

           WORK

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

           RESID

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

       Author
           Univ. of Tennessee


           Univ. of California Berkeley


           Univ. of Colorado Denver


           NAG Ltd.

       Definition at line 107 of file dtpt01.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/LIN/dtpt01.f(3)