Good. If you are using linux/unix I can send you the new version now, otherwise I hope to submit to CRAN in about 10 days. Do note that most people plot pointwise confidence intervals in this setting, but I think that simultaneous confidence bands do have advantages. Frank
Eleni Rapsomaniki-3 wrote > > Dear Professor Harrell, > > Once again thank you for your helpful reply. I could use rcs instead, so I > look forward to your latest rms release (soon I hope?) > Initially I favoured fractional polynomials thinking that the model would > be easier to present, but now I see that with either method unless one > plots the fitted function results are just as hard to interpret. That's > why the simultaneous CI plot will be very useful. > > Eleni > >> On Jan 9, 2012, at 8:45 AM, "Eleni Rapsomaniki" <[email protected]> >> wrote: >> >>> Dear R users, >>> >>> The package 'mfp' that fits fractional polynomial terms to predictors. >>> Example: >>> data(GBSG) >>> f <- mfp(Surv(rfst, cens) ~ fp(age, df = 4, select = 0.05) >>> + fp(prm, df = 4, select = 0.05), family = cox, data = >>> GBSG) >>> print(f) >>> >>> To describe the association between the original predictor, eg. age and >>> risk for different values of age I can plot it the polynomials and >>> fitted >>> coefficients as: >>> >>> plot(0.407*I((age/100)^-2) + -4.96*I((age/100)^-0.5) ~ age, GBSG) >>> >>> But I can't work out how to get a 95% confidence interval for this >>> curve... Any suggestions? I could bootstrap it, but is there a >>> mathematical solution? >>> >>> Many thanks >>> Eleni Rapsomaniki >>> Medical Statistician >>> UCL, London >>> >>> ______________________________________________ >>> R-help@ 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. >> > > ______________________________________________ > R-help@ 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. > ----- Frank Harrell Department of Biostatistics, Vanderbilt University -- View this message in context: http://r.789695.n4.nabble.com/Joint-confidence-interval-for-fractional-polynomial-terms-tp4278494p4280001.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ [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.
