Find the children of an internal node in a tree

Find the direct children of an internal node in a tree.

Usage

findChild(tree, node, use.alias = FALSE)

Arguments

tree: A phylo object.
node: Either the node number or node label of an internal node of tree.
use.alias: A logical scalar. If FALSE (default), the node label is used to name the output; otherwise, the alias of the node label is used. The alias of the node label is created by adding a prefix "alias_" to the node number.

Value

A vector of nodes. The numeric value is the node number, and the vector name is the corresponding node label. If a node has no label, it would have NA as name when use.alias = FALSE, and have the alias of the node label as name when use.alias = TRUE.

Author

Ruizhu Huang, Charlotte Soneson

Examples

suppressPackageStartupMessages({
    library(ggtree)
    library(TreeSummarizedExperiment)
})

data(tinyTree)
ggtree(tinyTree, branch.length = "none") +
    geom_text2(aes(label = node), color = "darkblue",
               hjust = -0.5, vjust = 0.7) +
    geom_text2(aes(label = label), color = "darkorange",
               hjust = -0.1, vjust = -0.7)


## Specify node numbers
findChild(tree = tinyTree, node = c(17, 12))
#> Node_13      t8 
#>      13       6 

## Name return values using aliases
findChild(tree = tinyTree, node = c(17, 12), use.alias = TRUE)
#> alias_13  alias_6 
#>       13        6 

## Specify node labels
findChild(tree = tinyTree, node = c("Node_17", "Node_12"))
#> Node_13      t8 
#>      13       6 

## Tips have no children
findChild(tree = tinyTree, node = "t4")
#> named integer(0)