deltas {ICGE}

Distance Between Groups

Description

Assume that n units are divided into k groups C1,...,Ck . Function deltas computes and returns the distance between each pair of groups. It uses the distances between pairs of units.

Usage

deltas(d, pert = "onegroup")

Arguments

d

a distance matrix or a dist object with distance information between units.

pert

an n-vector that indicates which group each unit belongs to. Note that the expected values of pert are numbers greater than or equal to 1 (for instance 1,2,3,4..., k). The default value indicates there is only one group in data.

Value

A matrix containing the distances between each pair of groups.

Author(s)

Itziar Irigoien [e-mail]; Konputazio Zientziak eta Adimen Artifiziala, Euskal Herriko Unibertsitatea (UPV/EHU), Donostia, Spain.

Conchita Arenas [e-mail]; Departament d'Estadistica, Universitat de Barcelona, Barcelona, Spain.

References

Arenas, C. and Cuadras, C.M. (2002). Some recent statistical methods based on distances. Contributions to Science, 2, 183–191.

Cuadras, C.M., Fortiana, J. and Oliva, F. (1997). The proximity of an individual to a population with applications in discriminant analysis. Journal of Classification, 14, 117–136.

See Also

vgeo, proxi

Examples

data(iris)
d <- dist(iris[,1:4])
deltas(d,iris[,5])