Fclust.index {fclust}

Cluster validity indexes

Description

Performs some cluster validity indexes for choosing the optimal number of clusters k.

Usage

 Fclust.index (fclust.obj, index, alpha)

Arguments

fclust.obj

Object of class fclust

index

Cluster validity indexes to select the number of clusters: PC (partition coefficient), PE (partition entropy), MPC (modified partition coefficient), SIL (silhouette), SIL.F (fuzzy silhouette), XB (Xie and Beni),ALL for all the indexes (default: "ALL")

alpha

Weighting coefficient for the fuzzy silhouette index SIL.F (default: 1)

Details

index is not case-sensitive.

Value

out.index

Vector containing the index values

Author(s)

Paolo Giordani, Maria Brigida Ferraro, Alessio Serafini

See Also

PC, PE, MPC, SIL, SIL.F, XB, Fclust, Mc

Examples

## McDonald's data
data(Mc)
names(Mc)
## data normalization by dividing the nutrition facts by the Serving Size (column 1)
for (j in 2:(ncol(Mc)-1))
Mc[,j]=Mc[,j]/Mc[,1]
## removing the column Serving Size
Mc=Mc[,-1]
## fuzzy k-means
## (excluded the factor column Type (last column))
clust=FKM(Mc[,1:(ncol(Mc)-1)],k=6,m=1.5,stand=1)
## cluster validity indexes
all.indexes=Fclust.index(clust)
## Xie and Beni cluster validity index
XB.index=Fclust.index(clust,'XB')