Zero-inflated gamma distribution

Density, distribution function, and random generation for the zero-inflated gamma distribution.

Usage

dzigamma(x, shape, scale, zeroprob = 0, log = FALSE)

pzigamma(q, shape, scale, zeroprob = 0, lower.tail = TRUE, log.p = FALSE)

rzigamma(n, shape, scale, zeroprob = 0)

Arguments

x, q

vector of quantiles

shape

positive shape parameter

scale

positive scale parameter

zeroprob

zero-inflation probability between 0 and 1.

log, log.p

logical; if TRUE, probabilities/ densities \(p\) are returned as \(\log(p)\).

lower.tail

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

n

number of random values to return

Value

dzigamma gives the density, pzigamma gives the distribution function, and rzigamma generates random deviates.

Details

This implementation allows for automatic differentiation with RTMB.

Examples

x <- rzigamma(1, 1, 1, 0.5)
d <- dzigamma(x, 1, 1, 0.5)
p <- pzigamma(x, 1, 1, 0.5)