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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