ztpln (version 0.1.3)

dztpln: The zero-truncated compund poisson-lognormal distributions

Description

Density function and random generation for Zero-Trauncated Poisson Lognormal distribution with parameters mu and sd sig.

Usage

dztpln(x, mu, sig, log = FALSE, type1 = TRUE)
rztpln(n, mu, sig, type1 = TRUE)

Value

dztpln gives the (log) density and rztpln generates random variates.

Arguments

x

vector of (non-negative integer) quantiles.

mu

mean of lognormal distribution.

sig

standard deviation of lognormal distribution.

log

logical; if TRUE, probabilities p are given as log(p).

type1

logical; if TRUE, Use type 1 ztpln else use type 2.

n

number of random values to return.

Details

A compound Poisson-lognormal distribution is a Poisson probability distribution where its parameter \(\lambda\) is a random variable with lognormal distribution, that is to say \(log\lambda\) are normally distributed with mean \(\mu\) and variance \(\sigma^2\) (Bulmer 1974). The zero-truncated Poisson-lognormal distribution can be derived from a zero-truncated Poisson distribution.

Type 1 ZTPLN truncates zero based on Poisson-lognormal distribution and type 2 ZTPLN truncates zero based on zero-truncated Poisson distribution. For mathematical details, please see vignette("ztpln")

References

Bulmer, M. G. 1974. On Fitting the Poisson Lognormal Distribution to Species-Abundance Data. Biometrics 30:101-110.

See Also

dztplnm

Examples

rztpln(n = 10, mu = 0, sig = 1, type1 = TRUE)
rztpln(n = 10, mu = 6, sig = 4, type1 = TRUE)
dztpln(x = 1:5, mu = 1, sig = 2)