最近在学习广义相加模型Generalized Additive Model, R 里面有个GAM 包，没有手册，详细操作可以参考本书第七章。
本书作者Chambers是R核心组员，S语言发明者。
坛子里有个pdf版，可惜是双页联排，看着费劲，做了个排版清晰带书签的版本。
参考WIKI: R is an implementation of the S programming language combined with S was created by John Chambers while at Bell Labs. There are some important differences, but much of the code written for S runs unaltered.[8]