Add piecewise regression example

We can define

def truncate(x, l):
    x = (x - l) * (x >= l)
    return x

And then simply do

formula = "response ~ x + truncate(x, 10) + truncate(x, 20)"

[tomicapretto]

I like when people get involved in the issues and propose new ideas. I really appreciate your comments. So please feel free to share when you want to propose something.

To be a little clearer, I’m not saying that we should only have the example using truncated(). What I’m saying is that we could have both, and explain the connection between them 😉

[hadjipantelis]

Fair points. I appreciate that my proposition might be a tad bullish regarding people’s familiarity with splines use.