TESTING/LIN/dppt02.f(3)

NAME
TESTING/LIN/dppt02.f

SYNOPSIS

  Functions/Subroutines
subroutine dppt02 (uplo, n, nrhs, a, x, ldx, b, ldb, rwork, resid)
DPPT02

Function/Subroutine Documentation

  subroutine dppt02 (character uplo, integer n, integer nrhs, double precision, dimension( * ) a, double precision, dimension( ldx, * ) x, integer ldx, double precision, dimension( ldb, * ) b, integer ldb, double precision, dimension( * ) rwork, double precision resid)

DPPT02

Purpose:

     DPPT02 computes the residual in the solution of a symmetric system
     of linear equations  A*x = b  when packed storage is used for the
     coefficient matrix.  The ratio computed is
        RESID = norm(B - A*X) / ( norm(A) * norm(X) * EPS),
     where EPS is the machine precision.

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.

    NRHS

              NRHS is INTEGER
              The number of columns of B, the matrix of right hand sides.
              NRHS >= 0.

    A

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

    X

              X is DOUBLE PRECISION array, dimension (LDX,NRHS)
              The computed solution vectors for the system of linear
              equations.

    LDX

              LDX is INTEGER
              The leading dimension of the array X.   LDX >= max(1,N).

    B

              B is DOUBLE PRECISION array, dimension (LDB,NRHS)
              On entry, the right hand side vectors for the system of
              linear equations.
              On exit, B is overwritten with the difference B - A*X.

    LDB

              LDB is INTEGER
              The leading dimension of the array B.  LDB >= max(1,N).

    RWORK

              RWORK is DOUBLE PRECISION array, dimension (N)

    RESID

              RESID is DOUBLE PRECISION
              The maximum over the number of right hand sides of
              norm(B - A*X) / ( norm(A) * norm(X) * EPS ).

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 120 of file dppt02.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.