fitPS (version 1.0.1)

rZIzeta: Generate zero inflated zeta random variates

Description

Generate zero inflated zeta random variates

Usage

rZIzeta(n, pi = 0.5, shape = 1, offset = 0)
rzizeta(n, pi = 0.5, shape = 1, offset = 0)
rzizeta(n, pi = 0.5, shape = 1, offset = 0)

Value

a vector of random variates from a zero-inflated zeta model

Arguments

n

the number of observations.

pi

the mixing parameter for the zero-inflated zeta model---must be in (0, 1).

shape

the shape parameter for the zero-inflated zeta. Must be greater than zero.

offset

the zeta distribution returns random variates that are greater than, or equal to one. If the offset is greater than 0, then the distribution is anchored on (has minimum value of) 1 - offset.

Details

Technically this function returns values from the one-inflated zeta distribution. However, if offset is greater than zero (and typically we expect it to be 1), then the minimium random variate value is 1 - offset. We chose the name "zero-inflated zeta" as more people are familiar with zero-inflated models.

Examples

data(Psurveys)
roux = Psurveys$roux
fit.zi = fitZIDist(roux)
x = rZIzeta(n = sum(roux$data$rn), pi = fit.zi$pi, shape = fit.zi$shape)
table(x)