PredX returns values outside of data range

[Tim Wessman]

When implementing this we had some long discussions about what to do here and couldn't come up with a good solution. There really isn't a "nice" way to do this since you could just as easily want the "other" answer. It gets even more tricky when you support N degree polynomials or trig fits.

What we basically decided was that just "looking at the plot" was a perfectly acceptable solution.