TESTING/LIN/dtrt06.f(3)    Library Functions Manual    TESTING/LIN/dtrt06.f(3)

NAME
       TESTING/LIN/dtrt06.f

SYNOPSIS
   Functions/Subroutines
       subroutine dtrt06 (rcond, rcondc, uplo, diag, n, a, lda, work, rat)
           DTRT06

Function/Subroutine Documentation
   subroutine dtrt06 (double precision rcond, double precision rcondc,
       character uplo, character diag, integer n, double precision, dimension(
       lda, * ) a, integer lda, double precision, dimension( * ) work, double
       precision rat)
       DTRT06

       Purpose:


            DTRT06 computes a test ratio comparing RCOND (the reciprocal
            condition number of a triangular matrix A) and RCONDC, the estimate
            computed by DTRCON.  Information about the triangular matrix A is
            used if one estimate is zero and the other is non-zero to decide if
            underflow in the estimate is justified.

       Parameters
           RCOND

                     RCOND is DOUBLE PRECISION
                     The estimate of the reciprocal condition number obtained by
                     forming the explicit inverse of the matrix A and computing
                     RCOND = 1/( norm(A) * norm(inv(A)) ).

           RCONDC

                     RCONDC is DOUBLE PRECISION
                     The estimate of the reciprocal condition number computed by
                     DTRCON.

           UPLO

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

           DIAG

                     DIAG is CHARACTER
                     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.

           A

                     A is DOUBLE PRECISION array, dimension (LDA,N)
                     The triangular matrix A.  If UPLO = 'U', the leading n by n
                     upper triangular part of the array A contains the upper
                     triangular matrix, and the strictly lower triangular part of
                     A is not referenced.  If UPLO = 'L', the leading n by n lower
                     triangular part of the array A contains the lower triangular
                     matrix, and the strictly upper triangular part of A is not
                     referenced.  If DIAG = 'U', the diagonal elements of A are
                     also not referenced and are assumed to be 1.

           LDA

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

           WORK

                     WORK is DOUBLE PRECISION array, dimension (N)

           RAT

                     RAT is DOUBLE PRECISION
                     The test ratio.  If both RCOND and RCONDC are nonzero,
                        RAT = MAX( RCOND, RCONDC )/MIN( RCOND, RCONDC ) - 1.
                     If RAT = 0, the two estimates are exactly the same.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 119 of file dtrt06.f.

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

LAPACK                          Version 3.12.0         TESTING/LIN/dtrt06.f(3)