I have a graph which looks like hyperbole. I'd like to fit a straight line to the lower segment going to infinity, approaching the X axis -- I'm interested in the angle. If I'd do it manually, I'd cut off a certain initial part of the range, [0..x_min], and then do an lm with the rest. Yet I wonder whether those "curve fitting" packages mentioned earlier do something similar automatically? Cheers, Alexy