dendextendRcpp (version 0.5.0)

dendextendRcpp_cut_lower_fun: Cut a dendrogram using Rcpp - and run a function on the output

Description

Cuts the a tree at height h and returns a list with the FUN function implemented on all the sub trees created by cut at height h. This is used for creating a cutree.dendrogram function, by using the labels function as FUN. This is the Rcpp version of the function, offering a 10-60 times improvement in speed (depending on the tree size it is used on).

Usage

dendextendRcpp_cut_lower_fun(tree, h, FUN = labels, warn = FALSE, ...)

Value

A list with the output of running FUN on each of the sub trees derived from cutting "tree"

See Also

labels, dendrogram, cutree (in dendextend), cutree (in stats)

Examples

dend = as.dendrogram(hclust(dist(iris[1:4,-5])))
dendextendRcpp::Rcpp_cut_lower(dend, .4)
dendextendRcpp::Rcpp_cut_lower(dend, .4, FALSE)
# this is really cool!
dendextendRcpp_cut_lower_fun(dend, .4, labels)
lapply(cut(dend, h = .4)$lower, labels)
dendextendRcpp_cut_lower_fun(dend, .4, order.dendrogram)

# require(dendextend)
   require(dendextendRcpp)
   dend_big = as.dendrogram(hclust(dist(iris[1:150,-5])))
   require(microbenchmark)
   microbenchmark(old_cut_lower_fun(dend_big,.1),
                  dendextendRcpp::dendextendRcpp_cut_lower_fun(dend_big,.1),
                     times = 100)
   # about 7-15 times faster. It is faster the larger the tree is, and the lower h is.