DTPT06 computes a test ratio comparing RCOND (the reciprocal


 condition number of a triangular matrix A) and RCONDC, the estimate


 computed by DTPCON.  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.

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


          DTPCON.

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.

AP

          AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)


          The 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.

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.

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