findrep: Finding representatives for cluster border
Description
Finds representative objects for the border of a cluster and the
within-cluster variance as defined in the framework of the cdbw
cluster validation index (and meant to be used in that context).
vector of integers with length =nrow(x);
indicating the cluster for each observation.
cluster
integer. Number of cluster to be treated.
r
integer. Number of representatives.
p
integer. Number of dimensions.
n
integer. Number of observations.
nc
integer. Number of observations in cluster.
Value
List with components
repc
vector of index of representatives (out of all
observations).
repx
vector of index of representatives (out of only the
observations in cluster).
maxr
number of representatives (this can be smaller than
r if fewer pairwise different observations are in
cluster.
wvar
estimated average within-cluster squared distance to mean.
References
Halkidi, M. and Vazirgiannis, M. (2008) A density-based cluster
validity approach using multi-representatives. Pattern
Recognition Letters 29, 773-786.
Halkidi, M., Vazirgiannis, M. and Hennig, C. (2015) Method-independent
indices for cluster validation. In C. Hennig, M. Meila, F. Murtagh,
R. Rocci (eds.) Handbook of Cluster Analysis, CRC
Press/Taylor & Francis, Boca Raton.