Re: [R] smoothing splines and degrees of freedom

From: Spencer Graves <spencer.graves_at_pdf.com>
Date: Fri 30 Jun 2006 - 00:36:02 EST

          The help page for 'smooth.spline' says the argument 'df' is 'the desired equivalent number of degrees of freedom (trace of the smoother matrix).' It also explains that the output of 'smooth.spline' includes a component 'fit', and two components of 'fit' are 'knot' and 'coef'. To learn more, you can run the examples, examine 'str(cars.spl)' and the other objects produced by those examples. You can also read more in the references cited there.

          If you would like further help from this group, please submit another question, preferably after first reading the posting guide! "www.R-project.org/posting-guide.html". There is substantial but anecdotal evidence to suggest that posts more consistent with that guide tend to get better answers quicker. For example, if the above does NOT answer your question, I believe you would have gotten a better reply if you had provided a simple, self-contained example, rather than having me rely on one from the 'example' section of the 'smooth.spline' help page.

	  Hope this helps.
	  Spencer Graves


Steven Shechter wrote:
> Hi,
> If I set df=2 in my smooth.spline function, is that equivalent to running
> a linear regression through my data? It appears that df=# of data points
> gives the interpolating spline and that df = 2 gives the linear
> regression, but I just want to confirm this.
>
> Thank you,
> Steven
>
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R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Jun 30 04:12:13 2006

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