NoncenHypergeom {MCMCpack} | R Documentation |

## The Noncentral Hypergeometric Distribution

### Description

Evaluates the density at a single point or all points, and generate random
draws from the Noncentral Hypergeometric distribution.

### Usage

dnoncenhypergeom(x=NA, n1, n2, m1, psi)
rnoncenhypergeom(n, n1, n2, m1, psi)

### Arguments

`x` |
The location to evaluate the density. If `x` is NA,
then a matrix is returned with the density evaluated at all possible
points. |

`n` |
The number of draws to make from the distribution. |

`n1` |
The size of group one. |

`n2` |
The size of group two. |

`m1` |
The observed number of positive outcomes (in both groups). |

`psi` |
Odds ratio. |

### Details

The Noncentral Hypergeometric is particularly useful for conditional
inference for *(2 x 2)* tables. We use the
parameterization and algorithms of Liao and Rosen (2001). The
underlying R code is based on their published code. See their
article for details of the parameterization.

### Value

`dnoncenhypergeom`

evaluates the density at point `x`

,
or a matrix with
the first column containing the possible values of the random
variable, and the second column containing the probabilities.
`rnoncenhypergeom`

returns a list of `n`

random draws from
the distribution.

### Source

J. G. Liao and Ori Rosen. 2001. ``Fast and Stable Algorithms for Computing
and Sampling From the Noncentral Hypergeometric Distribution." *The
American Statistician.* 55: 366-369.

### Examples

density <- dnoncenhypergeom(NA, 500, 500, 500, 6.0)
draws <- rnoncenhypergeom(10, 500, 500, 500, 6.0)

[Package

*MCMCpack* version 0.5-2

Index]