我在 R 中执行一系列泊松回归,然后根据 AIC 对我的模型进行排名。但是我得到了这个结果:
> aictab(cand.set = Cand.models, sort = TRUE)
Model selection based on AICc :
K AICc Delta_AICc AICcWt Cum.Wt LL
Mod7 4 Inf NaN NaN NA -Inf
Mod6 3 Inf NaN NaN NA -Inf
Mod5 3 Inf NaN NaN NA -Inf
Mod4 3 Inf NaN NaN NA -Inf
Mod3 2 Inf NaN NaN NA -Inf
Mod2 2 Inf NaN NaN NA -Inf
Mod1 2 Inf NaN NaN NA -Inf
每个模型分别给出截距而不是 AIC 的结果...
> Cand.models[[1]]
Call: glm(formula = D ~ A, family = poisson(), data = d)
Coefficients:
(Intercept) Slope
-0.17356 0.07058
Degrees of Freedom: 251 Total (i.e. Null); 250 Residual
Null Deviance: 55.35
Residual Deviance: 54.99 AIC: Inf
当我对 family=gaussian(identity) 做同样的事情时,我得到了结果。当我进行泊松回归时,为什么 AIC 不起作用?
任何帮助,将不胜感激。