felix {VGAM} | R Documentation |
Felix Distribution Family Function
Description
Estimates the parameter of a Felix distribution by maximum likelihood estimation.
Usage
felix(lrate = extlogitlink(min = 0, max = 0.5), imethod = 1)
Arguments
lrate |
Link function for the parameter,
called |
imethod |
See |
Details
The Felix distribution is an important basic Lagrangian distribution. The density function is
f(y;a) =
\frac{ 1 }{((y-1)/2)!} y^{(y-3)/2} a^{(y-1)/2} \exp(-ay)
where y=1,3,5,\ldots
and
0 < a < 0.5
.
The mean is 1/(1-2a)
(returned as the fitted values).
Fisher scoring is implemented.
Value
An object of class "vglmff"
(see vglmff-class
).
The object is used by modelling functions
such as vglm
and vgam
.
Author(s)
T. W. Yee
References
Consul, P. C. and Famoye, F. (2006). Lagrangian Probability Distributions, Boston, USA: Birkhauser.
See Also
Examples
fdata <- data.frame(y = 2 * rpois(n = 200, 1) + 1) # Not real data!
fit <- vglm(y ~ 1, felix, data = fdata, trace = TRUE, crit = "coef")
coef(fit, matrix = TRUE)
Coef(fit)
summary(fit)