hybridHclust {hybridHclust} | R Documentation |
Top-down clustering (tsvq
) is applied to data with constraint that
mutual clusters cannot be divided. Within each mutual cluster, tsvq is re-applied to
yeild a top-down hybrid in which mutual cluster structure is retained.
hybridHclust(x, themc=NULL, trace=FALSE)
x |
A data matrix whose rows are to be clustered |
themc |
An object representing the mutual clusters in x, typically
generated by mutualCluster . If it is not provided, it will be calculated. |
trace |
Should internal steps be printed as they execute? |
A mutual cluster is a set of points that should never be broken (see help
for ‘mutualCluster’ for a more precise definition). hybridHcclust
uses this idea to
construct a top-down clustering in which mutual clusters are never broken.
This is achieved by temporarily “fusing” together all points in a
mutual cluster
so that they have equal coordinates, running tsvq
, and then
re-running tsvq
within each mutual cluster. The resultant top-down clusterings
are then “stitched” together to form a single top-down clustering.
Only maximal mutual clusters are constrained to not be broken. Thus if points A, B, C, D are a mutual cluster and points A, B are also a mutual cluster, only the four points will be forbidden from being broken.
A dendrogram in hclust
format.
Hugh Chipman
tsvq
x <- cbind(c(-1.4806,1.5772,-0.9567,-0.92,-1.9976,-0.2723,-0.3153), c( -0.6283,-0.1065,0.428,-0.7777,-1.2939,-0.7796,0.012)) hyb1 <- hybridHclust(x) par(mfrow=c(1,2)) plot(x, pch = as.character(1:nrow(x)), asp = 1) plot(hyb1) # also works mc1 <- mutualCluster(x) hyb1 <- hybridHclust(x,mc1)