Take a look at packages mgcv or gam (and probably others). Different smoothers are used, but it's nonlinear, nonparametric logistic regression. which is usually the important part. It also penalizes, which can be even more important than which smoother is used.
-- Bert On Sat, Jun 4, 2011 at 9:02 AM, David Winsemius <dwinsem...@comcast.net> wrote: > > On Jun 4, 2011, at 11:41 AM, zhu yao wrote: > >> Dear UseRs: >> >> Recently, I have read an article regarding the association between age and >> lymph node metastases. >> http://jco.ascopubs.org/content/27/18/2931.long >> In statistical analysis, the authors stated "Because a nonlinear >> relationship between age and lymph node involvement was expected based on >> existing literature, lymph node involvement was also regressed on age >> using >> nonparametric logistic regression based on locally weighted scatterplot >> smoothing (lowess)." >> <http://jco.ascopubs.org/content/27/18/2931.long#ref-11> >> Could someone explain nonparametric logistic regression based on locally >> weighted scatterplot smoothing (lowess)? >> Or it is nonparametric regression based on locally weighted scatterplot >> smoothing (lowess) >> > > One can use a logistic link and a local likelihood. Loader describes the > advantages of such a strategy and shows a worked example in pages 60-65 of > her text "Local Regression and Likelihood". But there is no apparent R > content in this question (and the authors of the above paper said they used > SAS) so this very much off-topic for this list. You really should start such > requests for explication by addressing the authors of the paper. Two other > web-based statistical sites for general or medical statistics questions can > be found at the GoogleGroups MedStats group and > http://stats.stackexchange.com/ . > > -- > David Winsemius, MD > West Hartford, CT > > ______________________________________________ > 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. > -- "Men by nature long to get on to the ultimate truths, and will often be impatient with elementary studies or fight shy of them. If it were possible to reach the ultimate truths without the elementary studies usually prefixed to them, these would not be preparatory studies but superfluous diversions." -- Maimonides (1135-1204) Bert Gunter Genentech Nonclinical Biostatistics ______________________________________________ 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.