Zero-Inflated Distributions

Density and distribution functions for zero-inflated distributions.

Usage

dzero_inflated_poisson(x, lambda, zi, log = FALSE)

pzero_inflated_poisson(q, lambda, zi, lower.tail = TRUE, log.p = FALSE)

qzero_inflated_poisson(p, lambda, zi, lower.tail = TRUE, log.p = FALSE)

dzero_inflated_negbinomial(x, mu, shape, zi, log = FALSE)

pzero_inflated_negbinomial(q, mu, shape, zi, lower.tail = TRUE, log.p = FALSE)

qzero_inflated_negbinomial(p, mu, shape, zi, lower.tail = TRUE, log.p = FALSE)

dzero_inflated_binomial(x, size, prob, zi, log = FALSE)

pzero_inflated_binomial(q, size, prob, zi, lower.tail = TRUE, log.p = FALSE)

qzero_inflated_binomial(p, size, prob, zi, lower.tail = TRUE, log.p = FALSE)

dzero_inflated_beta_binomial(x, size, mu, phi, zi, log = FALSE)

pzero_inflated_beta_binomial(
  q,
  size,
  mu,
  phi,
  zi,
  lower.tail = TRUE,
  log.p = FALSE
)

qzero_inflated_beta_binomial(
  p,
  size,
  mu,
  phi,
  zi,
  lower.tail = TRUE,
  log.p = FALSE
)

dzero_inflated_beta(x, shape1, shape2, zi, log = FALSE)

pzero_inflated_beta(q, shape1, shape2, zi, lower.tail = TRUE, log.p = FALSE)

qzero_inflated_beta(p, shape1, shape2, zi, lower.tail = TRUE, log.p = FALSE)

Arguments

x

Vector of quantiles.

zi

zero-inflation probability

log

Logical; If TRUE, values are returned on the log scale.

q

Vector of quantiles.

lower.tail

Logical; If TRUE (default), return P(X <= x). Else, return P(X > x) .

log.p

Logical; If TRUE, values are returned on the log scale.

p

Vector of probabilities.

mu, lambda

location parameter

shape, shape1, shape2

shape parameter

size

number of trials

prob

probability of success on each trial

phi

precision parameter

Details

The density of a zero-inflated distribution can be specified as follows. If \(x = 0\) set \(f(x) = \theta + (1 - \theta) * g(0)\). Else set \(f(x) = (1 - \theta) * g(x)\), where \(g(x)\) is the density of the non-zero-inflated part. For the zero-inflated negative binomial distribution, the quantile function has no known closed form and is therefore computed numerically.