margination {truecluster} | R Documentation |
Functions to calculate the number of possible groupings given fixed group sizes (margins).
nlabelation(...) lnlabelation(...) ldlabelation(...) nmargination(...) lnmargination(...) ldmargination(...)
... |
one or more vectors of group sizes |
Function nmargination
gives the number of possibles groupings (=cluster solutions) that have the input group sizes.
Function nlabelation
gives the number of possibles assignents to predefined (=labelled) groups of the requires sizes (more possibilities).
The ln-versions give the log instead, the ld-versions the logarithm dualis.
scalar
Jens Oehlschlägel
clusteration
, permutation
, combination
, choose
, lgamma
, absolute.entropy
, exact.margin.info
cat("There are 25 possibilities to make 3 clusters from 5 cases\n") nclusteration(5,3) cat(" 10 of sizes 3,1,1\n") nmargination(3,1,1) cat(" and 15 of sizes 2,2,1\n") nmargination(2,2,1) cat("By contrast there are 30 possibilities to assign 5 cases to 3 labelled groups a=2,b=2,c=1\n") nlabelation(2,2,1) n <- 250 k <- 5 i <- 1:(n/k) matplot(k*i, cbind( k^(i*k) , sapply(i, function(i){nclusteration(k*i, k)}) , sapply(i, function(i){nmargination(rep(i, k))}) ) , log="y", type="l" , lty=1:3, xlab="n" , ylab = "combinations" , main = "number of possible groupings" ) legend(n,1 , c(substitute(k^n, list(k=k)), expression("no restriction"), expression("equal sizes")) , lty=1:3, col=1:3, xjust=1, yjust=0 )