Feature request: show root edge

[richelbilderbeek]

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I did not read the documents, as the page is not found. I did read the documents at the present location

Describe you issue

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I would like to plot a phylogeny, including its root edge or stem.

# A phylogeny with a long stem
phylo <- ape::read.tree(text = "(A:1,B:1):20;")

This can easily be done in ape:

# Plot the phylogeny with the long stem with its stem visible
ape::plot.phylo(phylo, root.edge = TRUE); ape::add.scale.bar()

resulting in:

I was unable to find how achieve the same with ggtree.
As the question how to do so remains unanswered in the google group, I assume it cannot yet be done.
I could get an accent on the root:

# Plot the phylogeny with the long stem with its root node shown, 
# instead of drawing the root edge
ggtree::ggtree(phylo) + ggtree::geom_treescale() + ggtree::geom_rootpoint()

Now I have a workaround by using white edges, but I think ggtree is able to do better.

This Issue is similar to #95, except that I want to draw the root edge, instead of adding space at the center of a fan phylogeny.

Note that FigTree, as mentioned in the documentation does provide to display a stem

Ask in right place

• for bugs or feature requests, post here (github issue)
• for questions, please post to google group

As the same question has not been answered in the google group, I mark this as a feature request

[GuangchuangYu]

geom_rootedge was introduced in v >= 1.13.0.006.

## by default, use phylo$root.edge
ggtree(phylo) + geom_rootedge() + geom_treescale(-15, 1, offset=0.01, width=.5)

## you can also specify rootedge directly in geom_rootedge
ggtree(phylo) + geom_rootedge(3) + geom_treescale(-2, 1, offset=0.01, width=.5)