- an object of class \code{"phylo"} with the following components:
- \item{edge}{a two-column matrix of mode character where each row
- represents an edge of the tree; the nodes and the tips are
- symbolized with numbers (these numbers are not treated as numeric,
- hence the mode character); the nodes are represented with negative
- numbers (the root being \code{"-1"}), and the tips are represented with
- positive numbers. For each row, the first column gives the
- ancestor. This representation allows an easy manipulation of the
- tree, particularly if it is rooted.}
- \item{edge.length}{a numeric vector giving the lengths of the
- branches given by \code{edge}.}
- \item{tip.label}{a vector of mode character giving the names of the
- tips; the order of the names in this vector corresponds to the
- (positive) number in \code{edge}.}
- \item{node.label}{(optional) a vector of mode character giving the
- names of the nodes (set to \code{NULL} if not available in the file).}
- \item{root.edge}{(optional) a numeric value giving the length of the
- branch at the root is it exists (\code{NULL} otherwise).}
-
- If several trees are read in the file, the returned object is of class
- \code{"multiPhylo"}, and is a list of objects of class \code{"phylo"}.
-
- An attribute \code{"origin"} is further given to the returned object
- which gives the name of the source file (with its path). This is used
- to write a tree in a NEXUS file where all the original data must be
- written (not only the tree) in accordance to the specifications of
- Maddison et al. (1997).