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How to do model selection with Tweedie distributions?
I’m trying to do AICc model selection and model averaging with tweedie (compound Poisson) distributed data in R.
When to use a Tweedie generalized linear model?
The most interesting Tweedie families occur for var.power between 1 and 2. For these GLMs, the response distribution has mass at zero (i.e., it has exact zeros) but is otherwise continuous on the positive real numbers (Smyth, 1996; Hasan et al, 2012). These GLMs have been used to model rainfall for example.
Is there such a thing as a Tweedie GLM?
There are no theoretical Tweedie GLMs with var.power between 0 and 1 (Jorgensen 1987). The tweedie function will work for those values but the family should be interpreted in a quasi-likelihood sense. Theoretical Tweedie GLMs do exist for negative values of var.power, but they are of little practical application.
What are the values of the Tweedie function?
The Tweedie family of GLMs is discussed in detail by Dunn and Smyth (2018). Each value of var.power corresponds to a particular type of response distribution. The values 0, 1, 2 and 3 correspond to the normal distribution, the Poisson distribution, the gamma distribution and the inverse-Gaussian distribution respectively.
Which is the best model for GLm and AIC?
Because a HIGH likelihood means a better fit, the LOW AIC is the best model. The nice thing about AIC is that we can compare models that are not nested: ## df AIC ## glm (f3, family = binomial, data = Solea) 2 72.55999 ## glm (f2, family = binomial, data = Solea) 2 90.63224
How to use AICC with Tweedie in Mumin?
You can use AICtweedie directly in MuMIn’s functions, just specify it as a rank argument. Alternatively, you could write a wrapper around AICtweedie. Thanks for contributing an answer to Cross Validated!
How are Tweedie distributions related to power law?
Tweedie distributions are a family of distributions from the exponential dispersion family that have power-law mean-variance relationship: \\begin {align} \\mathbb E [X] &= \\mu \\\\ \\operatorname {Var} [… I am looking at homicide rates per US county in a given 3-yr period as a DV, against several demographic and political measures as IV.