GAM in gam and GAM in mgcv
The additive model fits a smoothing curve through the data. There are as many smoothing techniques as there are roads to Rome. In R, there are two main packages for GAM The gam package written by Hastie and Tibshirani and the mgcv package produced by Wood. Each package has its own charms. Readers familiar with the classical textbook from Hastie and Tibshirani 1990 may prefer the gam package as it follows the theory described in the book. Estimation of smoothers is done using a method called the...