Zero-inflated Poisson distribution

Probability mass function, distribution function, and random generation for the zero-inflated Poisson distribution.

Usage

dzipois(x, lambda, zeroprob = 0, log = FALSE)

pzipois(q, lambda, zeroprob = 0, lower.tail = TRUE, log.p = FALSE)

rzipois(n, lambda, zeroprob = 0)

Arguments

x, q

integer vector of counts

lambda

vector of (non-negative) means

zeroprob

zero-inflation probability between 0 and 1

log, log.p

logical; return log-density if TRUE

lower.tail

logical; if TRUE, probabilities are \(P[X <= x]\), otherwise, \(P[X > x]\).

n

number of random values to return.

Value

dzipois gives the probability mass function, pzipois gives the distribution function, and rzipois generates random deviates.

Details

This implementation allows for automatic differentiation with RTMB.

Examples

set.seed(123)
x <- rzipois(1, 0.5, 1)
d <- dzipois(x, 0.5, 1)
p <- pzipois(x, 0.5, 1)