object returned by function cls.scatt.data or cls.scatt.diss.mx.
intracls
string vector containing one or more names of intra cluster distances.
Available are:
1. if index.list is produced by cls.scatt.data:
complete | average | centroid,
2. if index.list is produced by cls.scatt.diss.mx:
complete | average.
intercls
string vector containing one or more names of inter cluster diameters.
Available are:
1. if index.list is produced by cls.scatt.data:
single | complete | average | centroid | aveToCent | hausdorff.
2. if index.list is produced by cls.scatt.diss.mx:
single | complete | average | hausdorff.
Details
Davies-Bouldin index is given by equation:
DB = (1/|C|) sum{forall i in 1:|C|} max[ i != j ] { (diam(Ci) + diam(Cj))/dist(Ci,Cj) }
i,j
- numbers of clusters which come from the same partitioning,
dist(Ck,Cl)
- inter cluster distance between clusters Ck and Cl,
diam(Cm)
- intra cluster diameter computed for cluster Cm,
|C|
- number of clusters.
Value
As output user gets the matrix of Davies-Bouldin indices.
Matrix dimension depends on how many diam and dist measures are chosen by the user,
normally dim(D)=c(length(intercls),length(intracls)).
Each pair: (inter-cluster dist, intra-cluster diam) have its own position in result matrix.