Dirichlet function

Dirichlet distribution

Density function, cumulative distribution function and random generation for the Dirichlet distribution.

ddirichlet(x, alpha, log = FALSE)

rdirichlet(n, alpha)

Arguments

• x: $k$-column matrix of quantiles.
• alpha: $k$-values vector or $k$-column matrix; concentration parameter. Must be positive.
• log: logical; if TRUE, probabilities p are given as log(p).
• n: number of observations. If length(n) > 1, the length is taken to be the number required.

Details

Probability density function

Examples

# Generating 10 random draws from Dirichlet distribution
# parametrized using a vector

rdirichlet(10, c(1, 1, 1, 1))

# or parametrized using a matrix where each row
# is a vector of parameters

alpha <- matrix(c(1, 1, 1, 1:3, 7:9), ncol = 3, byrow = TRUE)
rdirichlet(10, alpha)

References

Devroye, L. (1986). Non-Uniform Random Variate Generation. Springer-Verlag.