VGAM (version 1.1-9)

Zageom: Zero-Altered Geometric Distribution

Description

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

Usage

dzageom(x, prob, pobs0 = 0, log = FALSE)
pzageom(q, prob, pobs0 = 0)
qzageom(p, prob, pobs0 = 0)
rzageom(n, prob, pobs0 = 0)

Value

dzageom gives the density and

pzageom gives the distribution function,

qzageom gives the quantile function, and

rzageom generates random deviates.

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.

prob, log

Parameters from the ordinary geometric distribution (see dgeom).

pobs0

Probability of (an observed) zero, called \(pobs0\). The default value of pobs0 = 0 corresponds to the response having a positive geometric distribution.

Author

T. W. Yee

Details

The probability function of \(Y\) is 0 with probability pobs0, else a positive geometric(prob) distribution.

See Also

zageometric, zigeometric, rposgeom.

Examples

prob <- 0.35; pobs0 <- 0.05; x <- (-1):7
dzageom(x, prob = prob, pobs0 = pobs0)
table(rzageom(100, prob = prob, pobs0 = pobs0))

if (FALSE)  x <- 0:10
barplot(rbind(dzageom(x, prob = prob, pobs0 = pobs0),
                dgeom(x, prob = prob)), las = 1,
        beside = TRUE, col = c("blue", "orange"), cex.main = 0.7,
        ylab = "Probability", names.arg = as.character(x),
        main = paste("ZAG(prob = ", prob, ", pobs0 = ", pobs0,
                   ") [blue] vs",  " Geometric(prob = ", prob,
                   ") [orange] densities", sep = ""))