  We derive closed formulas for the condition number of a linear function of
the total least squares solution. Given an over determined linear system Ax=b,
we show that this condition number can be computed using the singular values
and the right singular vectors of [A,b] and A. We also provide an upper bound
that requires the computation of the largest and the smallest singular value of
[A,b] and the smallest singular value of A. In numerical examples, we compare
these values and the resulting forward error bounds with existing error
estimates.

Numerical Analysis