TESTING/LIN/cpst01.f(3)    Library Functions Manual    TESTING/LIN/cpst01.f(3)

NAME
       TESTING/LIN/cpst01.f

SYNOPSIS
   Functions/Subroutines
       subroutine cpst01 (uplo, n, a, lda, afac, ldafac, perm, ldperm, piv,
           rwork, resid, rank)
           CPST01

Function/Subroutine Documentation
   subroutine cpst01 (character uplo, integer n, complex, dimension( lda, * )
       a, integer lda, complex, dimension( ldafac, * ) afac, integer ldafac,
       complex, dimension( ldperm, * ) perm, integer ldperm, integer,
       dimension( * ) piv, real, dimension( * ) rwork, real resid, integer
       rank)
       CPST01

       Purpose:


            CPST01 reconstructs an Hermitian positive semidefinite matrix A
            from its L or U factors and the permutation matrix P and computes
            the residual
               norm( P*L*L'*P' - A ) / ( N * norm(A) * EPS ) or
               norm( P*U'*U*P' - A ) / ( N * norm(A) * EPS ),
            where EPS is the machine epsilon, L' is the conjugate transpose of L,
            and U' is the conjugate transpose of U.

       Parameters
           UPLO

                     UPLO is CHARACTER*1
                     Specifies whether the upper or lower triangular part of the
                     Hermitian 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 COMPLEX array, dimension (LDA,N)
                     The original Hermitian matrix A.

           LDA

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

           AFAC

                     AFAC is COMPLEX array, dimension (LDAFAC,N)
                     The factor L or U from the L*L' or U'*U
                     factorization of A.

           LDAFAC

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

           PERM

                     PERM is COMPLEX array, dimension (LDPERM,N)
                     Overwritten with the reconstructed matrix, and then with the
                     difference P*L*L'*P' - A (or P*U'*U*P' - A)

           LDPERM

                     LDPERM is INTEGER
                     The leading dimension of the array PERM.
                     LDAPERM >= max(1,N).

           PIV

                     PIV is INTEGER array, dimension (N)
                     PIV is such that the nonzero entries are
                     P( PIV( K ), K ) = 1.

           RWORK

                     RWORK is REAL array, dimension (N)

           RESID

                     RESID is REAL
                     If UPLO = 'L', norm(L*L' - A) / ( N * norm(A) * EPS )
                     If UPLO = 'U', norm(U'*U - A) / ( N * norm(A) * EPS )

           RANK

                     RANK is INTEGER
                     number of nonzero singular values of A.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 134 of file cpst01.f.

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

LAPACK                          Version 3.12.0         TESTING/LIN/cpst01.f(3)