Family functions for glmmTMB
nbinom2(link = "log")nbinom1(link = "log")
compois(link = "log")
truncated_compois(link = "log")
genpois(link = "log")
truncated_genpois(link = "log")
truncated_poisson(link = "log")
truncated_nbinom2(link = "log")
truncated_nbinom1(link = "log")
beta_family(link = "logit")
betabinomial(link = "logit")
tweedie(link = "log")
ziGamma(link = "inverse")
(character) link function for the conditional mean ("log", "logit", "probit", "inverse", "cloglog", "identity", or "sqrt")
returns a list with (at least) components
length-1 character vector giving the family name
length-1 character vector specifying the link function
a function of either 1 (mean) or 2 (mean and dispersion
parameter) arguments giving a value proportional to the
predicted variance (scaled by sigma(.))
If specified, the dispersion model uses a log link. Denoting the variance as \(V\), the dispersion parameter as \(\phi=\exp(\eta)\) (where \(\eta\) is the linear predictor from the dispersion model), and the predicted mean as \(\mu\):
(from base R): constant \(V=\phi\)
(from base R) phi is the shape parameter. \(V=\mu\phi\)
a modified version of Gamma that skips checks for zero values, allowing it to be used to fit hurdle-Gamma models
Negative binomial distribution: quadratic parameterization (Hardin & Hilbe 2007). \(V=\mu(1+\mu/\phi) = \mu+\mu^2/\phi\).
Negative binomial distribution: linear parameterization (Hardin & Hilbe 2007). \(V=\mu(1+\phi)\)
Conway-Maxwell Poisson distribution: parameterized with the exact mean (Huang 2017), which differs from the parameterization used in the COMPoissonReg package (Sellers & Shmueli 2010, Sellers & Lotze 2015). \(V=\mu\phi\).
Generalized Poisson distribution (Consul & Famoye 1992). \(V=\mu\exp(\eta)\). (Note that Consul & Famoye (1992) define \(\phi\) differently.)
Beta distribution: parameterization of Ferrari and Cribari-Neto (2004) and the betareg package (Cribari-Neto and Zeileis 2010); \(V=\mu(1-\mu)/(\phi+1)\)
Beta-binomial distribution: parameterized according to Morris (1997). \(V=\mu(1-\mu)(n(\phi+n)/(\phi+1))\)
Tweedie distribution: \(V=\phi\mu^p\). The power parameter is restricted to the interval \(1<p<2\)
Consul PC & Famoye F (1992). "Generalized Poisson regression model." Communications in Statistics: Theory and Methods 21:89<U+2013>109.
Ferrari SLP, Cribari-Neto F (2004). "Beta Regression for Modelling Rates and Proportions." J. Appl. Stat. 31(7), 799-815.
Hardin JW & Hilbe JM (2007). "Generalized linear models and extensions." Stata Press.
Huang A (2017). "Mean-parametrized Conway<U+2013>Maxwell<U+2013>Poisson regression models for dispersed counts." Statistical Modelling 17(6), 1-22.
Morris W (1997). "Disentangling Effects of Induced Plant Defenses and Food Quantity on Herbivores by Fitting Nonlinear Models." American Naturalist 150:299-327.
Sellers K & Lotze T (2015). "COMPoissonReg: Conway-Maxwell Poisson (COM-Poisson) Regression". R package version 0.3.5. https://CRAN.R-project.org/package=COMPoissonReg
Sellers K & Shmueli G (2010) "A Flexible Regression Model for Count Data." Annals of Applied Statistics 4(2), 943<U+2013>61. https://doi.org/10.1214/09-AOAS306.