[R] Splines under tension
Greg.Snow at imail.org
Wed May 12 20:37:30 CEST 2010
I think this last line is a fortune candidate:
It's not just that different disciplines rediscover the same ideas, they also relabel them.
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
greg.snow at imail.org
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Terry Therneau
> Sent: Wednesday, May 12, 2010 6:49 AM
> To: sam.e
> Cc: r-help at r-project.org
> Subject: Re: [R] Splines under tension
> ---begin included message ---
> Does anyone know if R has a function for splines under tension. I know
> there are numerous packages for spline interpolation within R i just
> can't find one that lets you determine the tension factor.
> In the statistics literature these are called "smoothing splines". For
> instance the s(x) construct in gam or pspline(x) in a coxph formula.
> There are multiple ways to specify the 'tension factor', many in the
> statistics community prefer the 'equivalent degrees of freedom' so you
> will often see df=___ in the examples. You can also directly enter a
> penalty mulitplier.
> To get a clearer answer you would need to give the explicit
> definition of "tension factor" from the literature you are quoting.
> It's not just that different disciplines rediscover the same ideas,
> also relabel them.
> Terry Therneau
> R-help at r-project.org mailing list
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