Smoother parameters #211
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Are there guidelines to help choose the k parameter for the smoothers? |
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Answer: Don’t need to because we implement penalized splines. But if you want to constrain it, you could use one of our parametric threshold functions, or specify smoothness manually. In that case, the same guidance for GAMs, etc, would probably apply here. We have implemented these smooths as P-splines, so they’re not super sensitive to ‘k’. In general, I think it’s good practice to crank them down low so that the smooth is biologically interpretable. If you have trouble fitting with the defaults, I think you can make ‘k’ 3 or 4, and fit something akin to a 2nd or 3rd order polynomial |
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Answer: Don’t need to because we implement penalized splines. But if you want to constrain it, you could use one of our parametric threshold functions, or specify smoothness manually. In that case, the same guidance for GAMs, etc, would probably apply here.
We have implemented these smooths as P-splines, so they’re not super sensitive to ‘k’. In general, I think it’s good practice to crank them down low so that the smooth is biologically interpretable. If you have trouble fitting with the defaults, I think you can make ‘k’ 3 or 4, and fit something akin to a 2nd or 3rd order polynomial