GAM and AIC: How can I do??? please

  Hello,  I'm a Korean researcher who have been started to learn the "R"
  package.

  I want to make gam model and AIC value of the model to compare several
  models.

  I did the GAM model, but there were error for AIC.

  SO, how can I do? pleas help me!!!



  I did like below;

  > a.fit <- gam(pi~ s(t1r), family = gaussian(link="log"))
  > summary(a.fit)

  Family: gaussian
  Link function: log

  Formula:
  pi ~ s(t1r)

  Parametric coefficients:
             Estimate  std. err.    t ratio    Pr(>|t|)
  constant   0.093105   0.005238      17.77    < 2.22e-16

  Approximate significance of smooth terms:
                edf       chi.sq     p-value
  s(t1r)      1.833       24.153     0.00014213

  R-sq.(adj) =  0.435   Deviance explained = 47.1%
  GCV score = 0.0010938   Scale est. = 0.00099053  n = 30

  > AIC(a.fit)

  Error in logLik(object) : no applicable method for "logLik"


  Eun A Kim, MD, MPH, Ph.D
  Senior Researcher
  Occupational safety and Health Research Institute
  Korea Occupational Safety and Health Agency
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