# The Dirichlet Distribution

### Description

Density function and random number generation for the Dirichlet distribution

### Usage

1 | ```
rdirichlet(n, alpha)
``` |

### Arguments

`n` |
number of random observations to draw |

`alpha` |
the Dirichlet distribution's parameters. Can be a vector (one set of parameters for all observations) or a matrix (a different set of parameters for each observation), see “Details” |

### Details

The Dirichlet distribution is a multidimensional generalization of the Beta distribution where each dimension is governed by an *alpha*-parameter.
Formally this is

*
D(α)=[Γ(∑α)/∏Γ(α)]∏ y^(α-1)
*

Usually, `alpha`

is a vector thus the same parameters will be used for all observations.
If `alpha`

is a matrix, a complete set of *alpha*-parameters must be supplied for each observation.

### Value

returns a matrix with random numbers according to the supplied alpha vector or matrix.

### Author(s)

Chong Wu

### Examples

1 2 | ```
X1 <- rdirichlet(100, c(5, 5, 10))
X1
``` |