# zanegbinUC: Zero-Altered Negative Binomial Distribution In VGAM: Vector Generalized Linear and Additive Models

## Description

Density, distribution function, quantile function and random generation for the zero-altered negative binomial distribution with parameter `pobs0`.

## Usage

 ```1 2 3 4``` ```dzanegbin(x, size, prob = NULL, munb = NULL, pobs0 = 0, log = FALSE) pzanegbin(q, size, prob = NULL, munb = NULL, pobs0 = 0) qzanegbin(p, size, prob = NULL, munb = NULL, pobs0 = 0) rzanegbin(n, size, prob = NULL, munb = NULL, pobs0 = 0) ```

## Arguments

 `x, q` vector of quantiles. `p` vector of probabilities. `n` number of observations. If `length(n) > 1` then the length is taken to be the number required. `size, prob, munb, log` Parameters from the ordinary negative binomial distribution (see `dnbinom`). Some arguments have been renamed slightly. `pobs0` Probability of zero, called pobs0. The default value of `pobs0 = 0` corresponds to the response having a positive negative binomial distribution.

## Details

The probability function of Y is 0 with probability `pobs0`, else a positive negative binomial(munb, size) distribution.

## Value

`dzanegbin` gives the density and `pzanegbin` gives the distribution function, `qzanegbin` gives the quantile function, and `rzanegbin` generates random deviates.

## Note

The argument `pobs0` is recycled to the required length, and must have values which lie in the interval [0,1].

## Author(s)

T. W. Yee

`Gaitnbinom`, `zanegbinomial`.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14``` ```munb <- 3; size <- 4; pobs0 <- 0.3; x <- (-1):7 dzanegbin(x, munb = munb, size = size, pobs0 = pobs0) table(rzanegbin(100, munb = munb, size = size, pobs0 = pobs0)) ## Not run: x <- 0:10 barplot(rbind(dzanegbin(x, munb = munb, size = size, pobs0 = pobs0), dnbinom(x, mu = munb, size = size)), beside = TRUE, col = c("blue", "green"), cex.main = 0.7, las = 1, ylab = "Probability", names.arg = as.character(x), main = paste("ZANB(munb = ", munb, ", size = ", size,", pobs0 = ", pobs0, ") [blue] vs", " NB(mu = ", munb, ", size = ", size, ") [green] densities", sep = "")) ## End(Not run) ```

### Example output ```Loading required package: stats4