Dear Thierry, Dear all, Many thanks for your replies.
Le jeudi 16 février 2023 à 10:39:34 UTC+1, Thierry Onkelinx <thierry.onkel...@inbo.be> a écrit : Dear Sacha, use glm() in this case. I'd rather code the covariable as TRUE / FALSE or as a factor. Best regards, ir. Thierry Onkelinx Statisticus / Statistician Vlaamse Overheid / Government of Flanders INSTITUUT VOOR NATUUR- EN BOSONDERZOEK / RESEARCH INSTITUTE FOR NATURE AND FOREST Team Biometrie & Kwaliteitszorg / Team Biometrics & Quality Assurance thierry.onkel...@inbo.be Havenlaan 88 bus 73, 1000 Brussel www.inbo.be /////////////////////////////////////////////////////////////////////////////////////////// To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey /////////////////////////////////////////////////////////////////////////////////////////// Op za 11 feb. 2023 om 18:35 schreef varin sacha via R-help <r-help@r-project.org>: > Dear R-experts, > > I am trying to fit a GAM with 2 binary predictors (variables coded 0,1). I > guess I cannot just smooth binary variables. By the way I code them as > 0=no,1=yes, then mgcv will think those variables are numeric. > I have tried to change 0 and 1 in no and yes. It does not work. > How to solve my problem. Here below my toy example. Many thanks. > > Best, > Sacha > > ######################## > y=c(0.02,0.1,0.04,0.07,0.09,0.1,0.054,0.076,0.0897,0.09,0.1,0.86,0.74,0.53,0.35,0.67,0.63,0.95,0.72,0.85) > x1=c(1,0,0,1,1,0,0,1,0,1,1,1,0,1,0,0,0,1,0,0) > x2=c(0,0,1,1,0,1,1,0,0,1,1,1,0,0,1,0,0,1,1,0) > > library(mgcv) > reg = gam(y ~ s(x1) +s(x2), family=binomial(link="logit")) > summary(reg) > ######################## > > > > ######################## > y=c(0.02,0.1,0.04,0.07,0.09,0.1,0.054,0.076,0.0897,0.09,0.1,0.86,0.74,0.53,0.35,0.67,0.63,0.95,0.72,0.85) > x1=c("yes","no","no","yes","yes","no","no","yes","no","yes","yes","yes","no","yes","no","no","no","yes","no","no") > x2=c("no","no","yes","yes","no","yes","yes","no","no","yes","yes","yes","no","no","yes","no","no","yes","yes","no") > library(mgcv) > reg = gam(y ~ s(x1) +s(x2), family=binomial(link="logit")) > summary(reg) > ######################## > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.