The Stanform gam() [gam package] has choices of spline or local-polynomial (defaulting to local-linear) smoothers. That's probably the best match for the description. It shouldn't be necessary to guess -- the paper should have cited the package -- but we know that is often missed.
-thomas On Sun, Jun 5, 2011 at 7:43 AM, Bert Gunter <gunter.ber...@gene.com> wrote: > 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. > -- Thomas Lumley Professor of Biostatistics University of Auckland ______________________________________________ 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.