Dear R-helpers,
My system: R 3.5.3 osx, mgcv 1.8-28 I try to build a model for five parameters Model = gam( Y ~ s(x1) + s(x2) + s(x3) + s(x4) + s(x5)) But, We found these five parameters have multicollinearity. We observed a significant correlation between these parameters. So, we performed a PCA to convert the set of five correlated air pollution variables into a set of linearly uncorrelated main variations. (PC1 and PC2) Then, we build the new GAM model using these two main variations as predictor variables. Model = gam( Y ~ s(PC1) + s(PC2)) Then, we can obtain the P value of PC1 and PC2. Approximate significance of smooth terms: edf Ref.df Chi.sq p-value s(PC1) 8.892 8.996 57402 <2e-16 *** s(PC2) 8.978 9.000 15125 <2e-16 *** But, we still cannot find out a way to calculate the P value for the original five parameter. Jason / Lin Jun [[alternative HTML version deleted]] ______________________________________________ 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.