Dear R-helpers, I need to fit natural cubic spline with specified number of knots. I expected 'splines' package will be helpful, but I am confused by its help. Is more detailed documentation available for it or could you recommend another R function? Best regards Ondrej Mikula
natural cubic splines
3 messages · Ondřej Mikula, Joshua Wiley, David Winsemius
Hi Ondrej, What documentation have you looked at? Does this help at all? require(splines) ?ns ## one example summary(lm(y ~ ns(x, df = 3), data = data.frame(y = runif(100), x = rbinom(100, 9, .25)^2))) ## built in examples example(ns) Also, I am very fond of the book, Modern Applied Statistics with S by Venables & Ripley. It has a section on splines that might help you. Cheers, Josh 2011/5/4 Ond?ej Mikula <onmikula at gmail.com>:
Dear R-helpers, I need to fit natural cubic spline with specified number of knots. I expected 'splines' package will be helpful, but I am confused by its help. Is more detailed documentation available for it or could you recommend another R function? Best regards Ondrej Mikula
______________________________________________ R-help at 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.
Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/
On May 4, 2011, at 8:34 AM, Joshua Wiley wrote:
Hi Ondrej, What documentation have you looked at? Does this help at all? require(splines) ?ns ## one example summary(lm(y ~ ns(x, df = 3), data = data.frame(y = runif(100), x = rbinom(100, 9, .25)^2))) ## built in examples example(ns) Also, I am very fond of the book, Modern Applied Statistics with S by Venables & Ripley. It has a section on splines that might help you.
Agree on that last point entirely. I understand that restricted cubic splines are another name for natural splines (but would welcome correction if that understanding is in error). They are used extensively in the rms/Hmisc package combination with the supporting text "Regression Modeling Strategies".
David > Cheers, > > Josh > > > 2011/5/4 Ond?ej Mikula <onmikula at gmail.com>: >> Dear R-helpers, >> I need to fit natural cubic spline with specified number of knots. I >> expected 'splines' package will be helpful, but I am confused by its >> help. Is more detailed documentation available for it or could you >> recommend another R function? >> Best regards >> Ondrej Mikuladucible code. >> > David Winsemius, MD Heritage Laboratories West Hartford, CT