# is.tree {oncomodel}

### Description

Tests whether a 2 x n matrix represents a rooted tree in the format accepted by the `oncomodel`

package.

### Usage

is.tree(tree)

### Arguments

- tree
- a 2 x n matrix.

### Details

In the accepted format, the columns of the integer matrix represent the edges of the tree, with the entry in the first row being closer to the root. The leaves have to be the smallest integers of the matrix. If an edge has a smaller column index than a second one, it may not be on the path from the second edge to the root (the order of the columns has to be compatible with the partial order of the edges of the tree).

Documentation reproduced from package oncomodel, version 1.0. License: GPL (>= 2)