Learn R Programming

prabclus (version 2.1-1)

specgroups: Average within-group distances for given groups

Description

Generates average within-group distances (overall and group-wise) from a dissimilarity matrix and a given grouping.

Usage

specgroups(distmat,groupvector, groupinfo)

Arguments

distmat
dissimilarity matrix or dist-object.
groupvector
integer vector. For every row of distmat, a number indicating the group membership.
groupinfo
list with components lg (levels of groupvector), ng (number of groups), nsg (vector of group sizes).

Value

  • A list with parameters
  • overalloverall average within-groups dissimilarity.
  • grvector of group-wise average within-group dissimilarities.

Examples

Run this code
data(siskiyou)
  x <- prabinit(prabmatrix=siskiyou, neighborhood=siskiyou.nb,
              distance="logkulczynski")  
  groupvector <- as.factor(siskiyou.groups)
  ng <- length(levels(groupvector))
  lg <- levels(groupvector)
  nsg <- numeric(0)
    for (i in 1:ng) nsg[i] <- sum(groupvector==lg[i])
  groupinfo <- list(lg=lg,ng=ng,nsg=nsg)
  specgroups(x$distmat,groupvector,groupinfo)

Run the code above in your browser using DataLab