[R] GAM without intercept reports a huge deviance
Hi all, I constructed a GAM model with a linear term and two smooth terms, all of them statistically significant but the intercept was not significant. The adjusted r2 of this model is 0.572 and the deviance 65.3. I decided to run the model again without intercept, so I used in R the following instruction: regression= gam(dependent~ +linear_independent +s(smooth_independent_1) +s(smooth_independent_2) -1,data=D) All the independent variables were significant. The adjusted r2 of this model is 0.552 and the deviance increased to 99.5! According to my knowledge, the adjusted r2 and the deviance should be more or less the same and this is the first time that I see this hug mismatch between r2 and deviance. What is causing this mismatch? Thank you so much. Ramón Filgueira -- View this message in context: http://r.789695.n4.nabble.com/GAM-without-intercept-reports-a-huge-deviance-tp4299609p4299609.html Sent from the R help mailing list archive at Nabble.com. __ 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.
[R] deviance and variance - GAM models
Hi all, This is pretty basic but I am not an expert and I couldn't find anything in the forum or my statistics book about it. I was reading a paper and the authors were using both explained deviance and explained variance as synonyms. They were describing a GAM regression. Is that right? I performed an analysis in R to take a look to the output of GAM regression and I think that: - 'R-sq. (adj)' is the percentage of variance explained by the regression, i.e., I can write The regression explains xx% of variance. - 'Deviance explained' is a simple measure of the quality of the fit but it is not related to the percentage of variance that is explained by the regression. Am I right? Thank you so much Ramón -- View this message in context: http://r.789695.n4.nabble.com/deviance-and-variance-GAM-models-tp4293293p4293293.html Sent from the R help mailing list archive at Nabble.com. __ 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.
