VGAM (version 0.7-1)

Zanegbin: Zero-Altered Negative Binomial Distribution

Description

Density, distribution function, quantile function and random generation for the zero-altered negative binomial distribution with parameter p0.

Usage

dzanegbin(x, p0, size, prob=NULL, munb=NULL, log = FALSE)
pzanegbin(q, p0, size, prob=NULL, munb=NULL)
qzanegbin(p, p0, size, prob=NULL, munb=NULL)
rzanegbin(n, p0, size, prob=NULL, munb=NULL)

Value

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

Details

The probability function of $Y$ is 0 with probability p0, else a positive $negative binomial(\mu_{nb}, size)$ distribution.

See Also

zanegbinomial, rposnegbin.

Examples

munb = 3; size = 4; p0 = 0.3; x = (-1):7
(ii = dzanegbin(x, p0=p0, munb=munb, size=size))
table(rzanegbin(100, p0=p0, munb=munb, size=size))

x = 0:10
barplot(rbind(dzanegbin(x, p0=p0, munb=munb, size=size),
              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(p0=", p0, ", munb=", munb, ", size=", size,
                   ") [blue] vs", " NB(mu=", munb, ", size=", size,
                   ") [green] densities", sep=""))