Basis Functions and Smoothing

R ile Genelleştirilmiş Katkılı Modeller (GAM'ler) ile Doğrusal Olmayan Modelle

Noam Ross

Senior Research Scientist, EcoHealth Alliance

Getting the right fit

$$\LARGE \text{Fit} = \text{Likelihood} - \lambda \times \text{Wiggliness}$$

Setting a fixed smoothing parameter

gam(y ~ s(x), data = dat, sp = 0.1)
gam(y ~ s(x, sp = 0.1), data = dat)

Smoothing via restricted maximum likelihood

gam(y ~ s(x), data = dat, method = "REML")

Setting number of basis functions

gam(y ~ s(x, k = 3), data = dat, method = "REML")

gam(y ~ s(x, k = 10), data = dat, method = "REML")

Use the defaults

gam(y ~ s(x), data = dat, method = "REML")

R ile Genelleştirilmiş Katkılı Modeller (GAM'ler) ile Doğrusal Olmayan Modelle