Issue #68 new
Jason Vander Heiden
created an issue

Using the data.tree package seems the easiest path from igraph to newick format:

library(igraph)
library(data.tree)
tree <- FromDataFrameNetwork(as_data_frame(graph))
ToNewick(tree, heightAttribute=NULL)

Not sure what you want to do with the heightAttribute, but you could base it of the "weight" column instead of excluding it.