optpart (version 3.0-3)

lambda: Goodman- Kruskal Lambda Index of Classification Association

Description

Compares two classifications by calculating the Goodman-Kruskal Index of association

Usage

lambda(x,y,digits=5)

Arguments

x

an object of class ‘clustering’, ‘partana’, ‘partition’ or a vector identifying membership of objects in classes with names attribute

y

an object of class ‘clustering’, ‘partana’, ‘partition’ or a vector identifying membership of objects in classes with names attribute

digits

the number of digits of the statsitic to report

Value

Prints a cross-tabulated table and the lambda statistic, and (invisibly) returns the lambda statistic

Details

lambda calculates the Goodman-Kruskal index of association:

\(\sum_i max_j (n_{ij}) + \sum_j max_i (n_{ij}) - max(n_{i,}) - max(n{_.j}) \over 2*\sum_i\sum_j n_{ij} - max(n_{i,}) - max(n{_.j)}\)

References

http://ecology.msu.montana.edu/labdsv/R

See Also

partition, optpart, slice,classmatch

Examples

# NOT RUN {
data(shoshveg)
dis.bc <- dsvdis(shoshveg,'bray/curtis')
opt.5 <- optpart(5,dis.bc)
pam.5 <- pam(dis.bc,5)
lambda(opt.5,pam.5)
# }