Collapse a sub dendrogram of adjacent labels within a dend

Given a dendrogram object, and a set of labels that are in the same sub-dendrogram, the function performs a recursive DFS algorithm to determine the sub-dendrogram which is composed of (exactly) all 'selected_labels'. It then squashes this sub-dendrogram, and returns the original dendrogram with the squashed dendrogram with it.

collapse_labels(dend, selected_labels, ...)

Arguments

dend: a dendrogram object
selected_labels: A character vector with the labels we expect to have in the sub-dendrogram. This doesn't have to be in the same order as in the dendrogram.
...: elipsis (passed to squash_dendrogram)

Value

Either the original dend. Or, if the labels properly are in the dend by each other, a dend with a squashed sub-dendrogram inside it.

Examples

library("dendextend")

set.seed(23235)
ss <- sample(1:150, 5)

# Getting the dend object
dend25 <- iris[ss, -5] %>%
   dist() %>%
   hclust() %>%
   as.dendrogram() %>% 
   set("labels", letters[1:5])

par(mfrow = c(1,4))
plot(dend25)
plot(collapse_labels(dend25, c("d", "e")))
plot(collapse_labels(dend25, c("c", "d", "e")))
plot(collapse_labels(dend25, c("c", "d", "e"), squashed_original_height=TRUE))