prabclus (version 2.3-4)

dicedist: Dice distance matrix

Description

Computes a distance derived from Dice's coincidence index between the columns of a 0-1-matrix.

Usage

dicedist(regmat)

Value

A symmetrical matrix of Dice distances.

Arguments

regmat

0-1-matrix. Columns are species, rows are regions.

Author

Christian Hennig https://www.unibo.it/sitoweb/christian.hennig/en

Details

The Dice distance between two species is 1 minus the Coincidence Index, which is (2*number of regions where both species are present)/(2*number of regions where both species are present plus number of regions where at least one species is present). This is S23 in Shi (1993).

References

Shi, G. R. (1993) Multivariate data analysis in palaeoecology and palaeobiogeography - a review. Palaeogeography, Palaeoclimatology, Palaeoecology 105, 199-234.

See Also

kulczynski,jaccard

Examples

options(digits=4)
data(kykladspecreg)
dicedist(t(kykladspecreg))