Read Tree File in Parenthetic Format
This function reads a file which contains one or several trees in parenthetic format known as the Newick or New Hampshire format.
read.tree(file = "", text = NULL, tree.names = NULL, skip = 0, comment.char = "#", keep.multi = FALSE, ...)
- a file name specified by either a variable of mode character,
or a double-quoted string; if
file = ""(the default) then the tree is input on the keyboard, the entry being terminated with a blank line.
- alternatively, the name of a variable of mode character
which contains the tree(s) in parenthetic format. By default, this
is ignored (set to
NULL, meaning that the tree is read in a file); if
- if there are several trees to be read, a vector of
mode character that gives names to the individual trees; if
NULL(the default), the trees are named
- the number of lines of the input file to skip before
beginning to read data (this is passed directly to
- a single character, the remaining of the line
after this character is ignored (this is passed directly to
tree.names = NULLthen single trees are returned in
"multiPhylo"format, with any name that is present (see details). Default is
- further arguments to be passed to
The default option for
file allows to type directly the tree on
the keyboard (or possibly to copy from an editor and paste in R's
console) with, e.g.,
mytree <- read.tree().
`read.tree' tries to represent correctly trees with a badly represented root edge (i.e. with an extra pair of parentheses). For instance, the tree "((A:1,B:1):10);" will be read like "(A:1,B:1):10;" but a warning message will be issued in the former case as this is apparently not a valid Newick format. If there are two root edges (e.g., "(((A:1,B:1):10):10);"), then the tree is not read and an error message is issued.
If there are any characters preceding the first "(" in a line then
this is assigned to the name. This is returned when a "multiPhylo"
object is returned and
tree.names = NULL.
- an object of class
"phylo"with the following components:
edge a two-column matrix of mode numeric where each row represents an edge of the tree; the nodes and the tips are symbolized with numbers; the tips are numbered 1, 2, ..., and the nodes are numbered after the tips. For each row, the first column gives the ancestor. edge.length (optional) a numeric vector giving the lengths of the branches given by
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
Nnode the number of (internal) nodes. node.label (optional) a vector of mode character giving the names of the nodes. root.edge (optional) a numeric value giving the length of the branch at the root if it exists.
- If several trees are read in the file, the returned object is of class
"multiPhylo", and is a list of objects of class
"phylo". The name of each tree can be specified by
tree.names, or can be read from the file (see details).
Felsenstein, J. The Newick tree format.
Olsen, G. Interpretation of the "Newick's 8:45" tree format standard.
Paradis, E. (2008) Definition of Formats for Coding Phylogenetic Trees
Paradis, E. (2012) Analysis of Phylogenetics and Evolution with R (Second Edition). New York: Springer.
### An extract from Sibley and Ahlquist (1990) s <- "owls(((Strix_aluco:4.2,Asio_otus:4.2):3.1,Athene_noctua:7.3):6.3,Tyto_alba:13.5);" cat(s, file = "ex.tre", sep = "") tree.owls <- read.tree("ex.tre") str(tree.owls) tree.owls tree.owls <- read.tree("ex.tre", keep.multi = TRUE) tree.owls names(tree.owls) unlink("ex.tre") # delete the file "ex.tre" ### Only the first three species using the option `text' TREE <- "((Strix_aluco:4.2,Asio_otus:4.2):3.1,Athene_noctua:7.3);" TREE tree.owls.bis <- read.tree(text = TREE) str(tree.owls.bis) tree.owls.bis