# Distance ratio test statistics for distance based clustering

### Description

Calculates the ratio between the `prop`

smallest and largest
distances of a distance matrix.

### Usage

1 | ```
distratio(distmat, prop = 0.25)
``` |

### Arguments

`distmat` |
symmetric distance matrix. |

`prop` |
numerical. Proportion between 0 and 1. |

### Details

Rounding is by `floor`

for small and `ceiling`

for large
distances.

### Value

A list with components

`dr` |
ratio of |

`lowmean` |
mean of |

`himean` |
mean of |

`prop` |
see above. |

### Author(s)

Christian Hennig chrish@stats.ucl.ac.uk http://www.homepages.ucl.ac.uk/~ucakche

### References

Hennig, C. and Hausdorf, B. (2004) Distance-based parametric bootstrap
tests for clustering of species ranges.
*Computational Statistics and Data Analysis* 45, 875-896.

### See Also

`prabtest`

### Examples

1 2 3 4 | ```
options(digits=4)
data(kykladspecreg)
j <- jaccard(t(kykladspecreg))
distratio(j)
``` |