R-users -- I would be interested in tools in R to fit the following gam model: logit(p) = a + f(x1) + f(x2) + f(x1,x2), where f(x1,x2) defines a surface. I have looked into the mgcv library, but it seems only to fit models of the form: logit(p) = a + f(x1) + f(x2) Any ideas? Cheers, Dan =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-Dan Powers Associate Professor, Sociology University of Texas at Austin -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
I don't know, but would the thin-plate splines in the funfit library do what you need? Ben Bolker On Wed, 16 May 2001, Daniel A. Powers wrote:> > R-users -- > > I would be interested in tools in R to fit the following gam model: > > logit(p) = a + f(x1) + f(x2) + f(x1,x2), > > where f(x1,x2) defines a surface. > > I have looked into the mgcv library, but it seems only to fit models of > the form: > > logit(p) = a + f(x1) + f(x2) > > Any ideas? > > Cheers, > Dan > > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-> Dan Powers > Associate Professor, Sociology > University of Texas at Austin > > > -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- > r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html > Send "info", "help", or "[un]subscribe" > (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch > _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._ >-- 318 Carr Hall bolker at zoo.ufl.edu Zoology Department, University of Florida http://www.zoo.ufl.edu/bolker Box 118525 (ph) 352-392-5697 Gainesville, FL 32611-8525 (fax) 352-392-3704 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
I don't think this actually is a GAM model > logit(p) = a + f(x1) + f(x2) + f(x1,x2) unless you mean f(x1*x2) or something like that instead of a completely general f(x1,x2); in particular it is equivalent to (*) logit(p) = f(x1,x2) with f(x1,x2) a surface. I'm not aware of anything for R that includes nonparametric bivariate logistic regression, unless maybe one of the fitting options in nnet would be appropriate for your data? tps in funfits can fit a bivariate surface but the only fitting option is least squares. > > R-users -- > > I would be interested in tools in R to fit the following gam model: > > logit(p) = a + f(x1) + f(x2) + f(x1,x2), > > where f(x1,x2) defines a surface. > > I have looked into the mgcv library, but it seems only to fit models of > the form: > > logit(p) = a + f(x1) + f(x2) > > Any ideas? > > Cheers, > Dan > ------------------------------------------------------- Stephen P. Ellner (spe2 at cornell.edu) Dept. of Ecology and Evolutionary Biology Corson Hall, Cornell University, Ithaca NY 14853-2701 Phone (607) 254-4221 FAX (607) 255-8088 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._