skbio.tree.TreeNode.get_max_distance#

TreeNode.get_max_distance(use_length=True)[source]#

Return the maximum path distance between any pair of tips.

This is also referred to as the diameter of a tree.

Parameters:

use_lengthbool, optional: Whether to return the sum of branch lengths (True, default) or the number of branches (False) connecting each pair of tips.

Added in version 0.6.3.

Returns:

float: The distance between the two most distant tips in the tree.
tuple of (TreeNode, TreeNode): The two most distant tips in the tree.

See also

distance
tip_tip_distances
compare_tip_distances

Notes

If a node does not have an associated branch length, 0 will be used.

When a tie is observed among more than one pair of tips, only one pair will be returned. The choice is stable. This often happens when use_length=False.

Examples

>>> from skbio import TreeNode
>>> tree = TreeNode.read(["((a:1,b:2)c:3,(d:4,e:5)f:6)root;"])
>>> dist, tips = tree.get_max_distance()
>>> dist
16.0
>>> [n.name for n in tips]
['e', 'b']