Simulate from the continuous parameter binomial

Draws counts from the continuous parameter binomial (CPB) or its zero-truncated variant.

Usage

rcpb(n, lambda, alpha, truncated = FALSE, support = c("ceiling", "floor"))

Arguments

n

Number of draws (recycled against lambda).

lambda

Rate parameter; a scalar or a length-n vector (see dcpb()).

alpha

Shape/dispersion parameter in (0, 1).

truncated

If TRUE, draw from the zero-truncated CPB.

support

The CPB's support, "ceiling" (King's CPB, the default) or "floor"; see cpb().

Value

An integer vector of counts.

Details

King's CPB has the support 0, ..., ceiling(lambda / (1 - alpha)), which contains 1 for every positive rate. The floor support, 0, ..., floor(lambda / (1 - alpha)), is {0} for a rate whose ceiling is below 1, so its zero-truncated distribution does not exist. With truncated = TRUE such a draw is set to 1 and a warning reports how many there were: the stated parameters give that count probability zero, so data simulated this way are not data from the model (in a simulation study, keep every ceiling at 1 or above).

Examples

set.seed(1)
table(rcpb(1000, lambda = 3, alpha = 0.5))
#> 
#>   0   1   2   3   4   5   6 
#>  20  96 220 302 264  84  14