TESTING/LIN/dtbt06.f(3)    Library Functions Manual    TESTING/LIN/dtbt06.f(3)

NAME
       TESTING/LIN/dtbt06.f

SYNOPSIS
   Functions/Subroutines
       subroutine dtbt06 (rcond, rcondc, uplo, diag, n, kd, ab, ldab, work,
           rat)
           DTBT06

Function/Subroutine Documentation
   subroutine dtbt06 (double precision rcond, double precision rcondc,
       character uplo, character diag, integer n, integer kd, double
       precision, dimension( ldab, * ) ab, integer ldab, double precision,
       dimension( * ) work, double precision rat)
       DTBT06

       Purpose:


           !>
           !> DTBT06 computes a test ratio comparing RCOND (the reciprocal
           !> condition number of a triangular matrix A) and RCONDC, the estimate
           !> computed by DTBCON.  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
           !>          DTBCON.
           !>

           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.
           !>

           KD

           !>          KD is INTEGER
           !>          The number of superdiagonals or subdiagonals of the
           !>          triangular band matrix A.  KD >= 0.
           !>

           AB

           !>          AB is DOUBLE PRECISION array, dimension (LDAB,N)
           !>          The upper or lower triangular band matrix A, stored in the
           !>          first kd+1 rows of the array. The j-th column of A is stored
           !>          in the j-th column of the array AB as follows:
           !>          if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;
           !>          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).
           !>

           LDAB

           !>          LDAB is INTEGER
           !>          The leading dimension of the array AB.  LDAB >= KD+1.
           !>

           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 123 of file dtbt06.f.

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

LAPACK                          Version 3.12.0         TESTING/LIN/dtbt06.f(3)