On Mon, 7 Jan 2008, [EMAIL PROTECTED] wrote: > Jonas, > > In statistical sense polynomial is a linear regression fit. The function > that handles linear fitting is called lm. Here is how you can reproduce > your results: > > lm(y ~ x + I(x^2) + I(x^3)) > > Unless you are really after the polynomial coefficients it is probably > better to use orthogonal polynomials. You can get this fit by doing > > lm(y ~ poly(x, 3))
And if you are, y ~ poly(x, 3, raw=TRUE) is simpler to type and comprehend. > > Check out help pages for lm and poly. Hope this helps, > > Andy > > __________________________________ > Andy Jaworski > 518-1-01 > Process Laboratory > 3M Corporate Research Laboratory > ----- > E-mail: [EMAIL PROTECTED] > Tel: (651) 733-6092 > Fax: (651) 736-3122 > > > > "Jonas Malmros" > <[EMAIL PROTECTED] > ail.com> To > Sent by: [email protected] > [EMAIL PROTECTED] cc > project.org > Subject > [R] Polynomial fitting > 01/07/2008 09:16 > AM > > > > > > > > > I wonder how one in R can fit a 3rd degree polynomial to some data? > > Say the data is: > > y <- c(15.51, 12.44, 31.5, 21.5, 17.89, 27.09, 15.02, 13.43, 18.18, 11.32) > x <- seq(3.75, 6, 0.25) > > And resulting degrees of polynomial are: > > 5.8007 -91.6339 472.1726 -774.2584 > > THanks in advance! > > > > -- > Jonas Malmros > Stockholm University > Stockholm, Sweden > > ______________________________________________ > [email protected] 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. > > ______________________________________________ > [email protected] 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. > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [email protected] 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.
