exppoisson {VGAM} | R Documentation |
Estimates the two parameters of the exponential Poisson distribution by maximum likelihood estimation.
exppoisson(llambda = "loge", lbetave = "loge", elambda = list(), ebetave = list(), ilambda = 1.1, ibetave = 2, zero = NULL)
llambda, lbetave |
Link function for the two positive parameters.
See |
elambda, ebetave |
List. Extra argument for each of the links.
See |
ilambda, ibetave |
Numeric.
Initial values for the |
zero |
The exponential Poisson distribution has density function
f(y; a = shape, b = scale) = (a*b/(1 - e^(-a))) * e^{-a - b*y + a * e^(-b*y)}
where y > 0 and the
parameters shape, a,
and scale, b, are positive.
The distribution implies a population facing discrete
hazard rates which are multiples of a base hazard.
This VGAM family function requires the hypergeo package
(to use their genhypergeo
function).
An object of class "vglmff"
(see vglmff-class
).
The object is used by modelling functions such as vglm
and vgam
.
This VGAM family function does not work properly!
J. G. Lauder, jamesglauder@gmail.com
Kus, C., (2007). A new lifetime distribution. Computational Statistics and Data Analysis, 51, 4497–4509.
dexppois
,
exponential
,
poisson
.
## Not run: lambda = exp(1); betave = exp(2) rdata = data.frame(y = rexppois(n = 1000, lambda, betave)) library(hypergeo) fit = vglm(y ~ 1, exppoisson, rdata, trace = TRUE) c(with(rdata, mean(y)), head(fitted(fit), 1)) coef(fit, matrix = TRUE) Coef(fit) summary(fit) ## End(Not run)