VGAM (version 1.1-2)

otpospoisson: One-truncated Poisson Distribution

Description

Estimating the (single) parameter of the 1-truncated positive Poisson distribution.

Usage

otpospoisson(llambda = "loglink",
    type.fitted = c("mean", "lambda", "prob0", "prob1"),
    ilambda = NULL, imethod = 1, zero = NULL)

Arguments

llambda, type.fitted, ilambda

Same as pospoisson.

imethod, zero

Same as pospoisson.

Value

An object of class "vglmff" (see vglmff-class). The object is used by modelling functions such as vglm, and vgam.

Details

The 1-truncated positive Poisson distribution has support on 2, 3, …. It is a Poisson distribution but with the probability of a one or zero being 0. The other probabilities are scaled to add to unity. Some more details can be found at pospoisson. Multiple responses are permitted.

See Also

Otpospois, oipospoisson, simulate.vlm.

Examples

# NOT RUN {
odata <- data.frame(y1 = rotpospois(n = 1000, lambda = loglink(1, inverse = TRUE)))
ofit <- vglm(y1 ~ 1, otpospoisson, data = odata, trace = TRUE, crit = "c")
coef(ofit, matrix = TRUE)
Coef(ofit)
# }
# NOT RUN {
with(odata,
    hist(y1, prob = TRUE, breaks = seq(0.5, max(y1) + 0.5, by = 1),
         border = "blue"))
x <- seq(1, with(odata, max(y1)), by = 1)
with(odata, lines(x, dotpospois(x, Coef(ofit)[1]), col = "orange", type = "h", lwd = 2)) 
# }