ZIB() R function from [extraDistr]

Zero-inflated binomial distribution

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


dzib(x, size, prob, pi, log = FALSE)

pzib(q, size, prob, pi, lower.tail = TRUE, log.p = FALSE)

qzib(p, size, prob, pi, lower.tail = TRUE, log.p = FALSE)

rzib(n, size, prob, pi)

Arguments

x, q: vector of quantiles.
size: number of trials (zero or more).
prob: probability of success in each trial. 0 < prob <= 1.
pi: probability of extra zeros.
log, log.p: logical; if TRUE, probabilities p are given as log(p).
lower.tail: logical; if TRUE (default), probabilities are $P[X \le x]$

otherwise, $P[X > x]$ .
p: vector of probabilities.
n: number of observations. If length(n) > 1, the length is taken to be the number required.

Details

Probability density function

f(x) = \left\{\begin{array}{ll}\pi + (1 - \pi) (1-p)^n & x = 0 \\(1 - \pi) {n \choose x} p^x (1-p)^{n-x} & x > 0 \\\end{array}\right.f(x) = [if x = 0:] (1-\pi)+\pi * p^r [else:] (1-\pi) * dnbinom(x, size, prob)

Examples


x <- rzib(1e5, 10, 0.6, 0.33)
xx <- -2:20
plot(prop.table(table(x)), type = "h")
lines(xx, dzib(xx, 10, 0.6, 0.33), col = "red")

xx <- seq(0, 20, by = 0.01)
plot(ecdf(x))
lines(xx, pzib(xx, 10, 0.6, 0.33), col = "red")

ZIB function

Zero-inflated binomial distribution

Arguments

Details

Examples

See Also