On Wednesday 26 December 2007 04:14, Kunio takezawa wrote: > R-users > E-mail: r-help@r-project.org > My understanding is that package "mgcv" is based on > "Generalized Additive Models: An Introduction with R (by Simon N. Wood)". > On the page 126 of this book, eq(3.4) looks a quartic equation with respect > to > "x", not a cubic equation. I am wondering if all routines which uses > cubic splines in mgcv are based on this quartic equation. --- No, `mgcv' does not use the basis given on page 126. See sections 4.1.2-4.1.8 of the same book for the bases used.
> In my humble opinion, the '^4' in the first term > of the second line of this equation should be '^3'. --- Perhaps take a look at section 2.3.3 of Gu (2002) "Smoothing Spline ANOVA" for a bit more detail on this/ > > K. Takezawa -- > Simon Wood, Mathematical Sciences, University of Bath, Bath, BA2 7AY UK > +44 1225 386603 www.maths.bath.ac.uk/~sw283 ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
