ape (version 1.8-5)

rtree: Generates Random Trees

Description

These functions generate trees by splitting randomly the edges (rtree) or randomly clustering the tips (rcoal). rtree generates general (non-ultrametric) trees, and rcoal generates coalescent (ultrametric) trees.

Usage

rtree(n, rooted = TRUE, tip.label = NULL, br = runif, ...)
rcoal(n, tip.label = NULL, br = rexp, ...)

Arguments

n

an integer giving the number of tips in the tree.

rooted

a logical indicating whether the tree should be rooted (the default).

tip.label

a character vector giving the tip labels; if not specified, the tips "t1", "t2", ..., are given.

br

either an R function used to generate the branch lengths (rtree) or the coalescence times (rcoal), or NULL to gave no branch lengths in the tree.

...

further argument(s) to be passed to br.

Details

The trees generated are bifurcating. If rooted = FALSE in (rtree), the tree is trifurcating at its `root'.

The default function to generate branch lengths in rtree is runif. In rcoal rexp is used to generate the inter-node distances. If further arguments are passed to br, they need to be tagged (e.g., min = 0, max = 10).

Examples

layout(matrix(1:9, 3, 3))
### Nine random trees:
for (i in 1:9) plot(rtree(20))
### Nine random cladograms:
for (i in 1:9) plot(rtree(20, FALSE), type = "c")
### generate 4 random trees of bird orders:
data(bird.orders)
layout(matrix(1:4, 2, 2))
for (i in 1:4)
  plot(rcoal(23, tip.label = bird.orders$tip.label), no.margin = TRUE)
layout(matrix(1))