[Phylobase-devl] RootEdge returns a NULL?

[Sang Chul Choi]

Hi,

I want to get root node id or label.

 > g <- as(rcoal(10), "phylo4")
 > g
    species.name node ancestor branch.length node.type
1            N1   11       NA            NA      root
2            N2   12       11  0.0890298523  internal
...
 > RootEdge(g)
[1] NA

I am wondering if RootEdge should return 11 or "N1." It seems to  
return always NA. I am sorry if this is due to my lack of knowledge  
about phylobase package.

Thank you,

Sang Chul