Speed up dendrogram layout computation

[andremrsantos]

Hi,

I've recently been working with the package for plotting some tree and dendrogram data, but some of my trees are quite large, and computing their layout is becoming costly.

Reviewing the code, I notice the following line of code used to compute the nodes' position.

ggraph/R/layout_dendrogram.R

Line 54 in 1440221

full_lengths <- distances(graph, to = node_is_root(), weights = length)

I was wondering if you couldn't include the parameter mode = "in" to avoid the algorithm transverse the whole tree and reduce computing time? I did a quick test and it improved the execution time for my local function.

Thanks for everything and a great project 👍