AddTip: Add a tip to a phylogenetic tree

In TreeTools: Create, Modify and Analyse Phylogenetic Trees

Add a tip to a phylogenetic tree

Description

AddTip() adds a tip to a phylogenetic tree at a specified location.

Usage

AddTip(
  tree,
  where = sample.int(tree[["Nnode"]] * 2 + 2L, size = 1) - 1L,
  label = "New tip",
  nodeLabel = "",
  edgeLength = 0,
  lengthBelow = NULL,
  nTip = NTip(tree),
  nNode = tree[["Nnode"]],
  rootNode = RootNode(tree)
)

AddTipEverywhere(tree, label = "New tip", includeRoot = FALSE)

Arguments

tree	A tree of class phylo.
where	The node or tip that should form the sister taxon to the new node. To add a new tip at the root, use where = 0. By default, the new tip is added to a random edge.
label	Character string providing the label to apply to the new tip.
nodeLabel	Character string providing a label to apply to the newly created node, if tree$node.label is specified.
edgeLength	Numeric specifying length of new edge. If NULL, defaults to lengthBelow. This will become the default behaviour in a future release; please manually specify the desired behaviour in your code.
lengthBelow	Numeric specifying length below neighbour at which to graft new edge. Values greater than the length of the edge will result in negative edge lengths. If NULL, the default, the new tip will be added at the midpoint of the broken edge. If inserting at the root (where = 0), a new edge of length lengthBelow will be inserted. If NA, the new leaf will be attached adjacent to where; at internal nodes, this will result in polytomy.
nTip, nNode, rootNode	Optional integer vectors specifying number of tips and nodes in tree, and index of root node. Not checked for correctness: specifying values here yields a marginal speed increase at the cost of code safety.
includeRoot	Logical; if TRUE, each position adjacent to the root edge is considered to represent distinct edges; if FALSE, they are treated as a single edge.

Details

AddTip() extends bind.tree, which cannot handle single-taxon trees.

AddTipEverywhere() adds a tip to each edge in turn.

Value

AddTip() returns a tree of class phylo with an additional tip at the desired location.

AddTipEverywhere() returns a list of class multiPhylo containing the trees produced by adding label to each edge of tree in turn.

Author(s)

Martin R. Smith ([e-mail])

See Also

Add one tree to another: bind.tree()

Other tree manipulation: CollapseNode(), ConsensusWithout(), DropTip(), EnforceOutgroup(), ImposeConstraint(), KeptPaths(), KeptVerts(), LeafLabelInterchange(), MakeTreeBinary(), Renumber(), RenumberTips(), RenumberTree(), RootTree(), SortTree(), Subtree(), TipTimedTree(), TrivialTree

Examples

tree <- BalancedTree(10)

# Add a leaf below an internal node
plot(tree)
ape::nodelabels() # Identify node numbers 
node <- 15        # Select location to add leaf
ape::nodelabels(bg = ifelse(NodeNumbers(tree) == node, "green", "grey"))

plot(AddTip(tree, 15, "NEW_TIP"))

# Add edge lengths for an ultrametric tree
tree$edge.length <- rep(c(rep(1, 5), 2, 1, 2, 2), 2)

# Add a leaf to an external edge
leaf <- 5
plot(tree)
ape::tiplabels(bg = ifelse(seq_len(NTip(tree)) == leaf, "green", "grey"))

plot(AddTip(tree, 5, "NEW_TIP", edgeLength = NULL))

# Create a polytomy, rather than a new node
plot(AddTip(tree, 5, "NEW_TIP", edgeLength = NA))

# Set up multi-panel plot
oldPar <- par(mfrow = c(2, 4), mar = rep(0.3, 4), cex = 0.9)

# Add leaf to each edge on a tree in turn
backbone <- BalancedTree(4)
# Treating the position of the root as instructive:
additions <- AddTipEverywhere(backbone, includeRoot = TRUE)
xx <- lapply(additions, plot)

par(mfrow = c(2, 3))
# Don't treat root edges as distinct:
additions <- AddTipEverywhere(backbone, includeRoot = FALSE)
xx <- lapply(additions, plot)

# Restore original plotting parameters
par(oldPar)

TreeTools documentation built on Aug. 8, 2025, 7:18 p.m.