I know there are two versions of gam in R. One is in library(mgcv) and one is in library(gam). The one in mgcv can automatically calculate the smoothing parameter. However, the one in gam can't although it can incorporate a larger variety of smoothers (besides spline). Can anybody educate me if there is a way to do smoothing parameter selection in gam from library(gam)? I know I can always program cross-validation by myself. But it might be more friendly for the software if it can take this into account automatically. (like gam in library(mgcv))