Calculate the fraction of internal nodes with an imbalance greater than or equal to a given threshold.
nodeImbFrac(tree, threshold)Arguments
- tree
a tree of class
phyloorphylo4. The tree should be binary and rooted; if not it will be coerced into a binary rooted tree using multi2di, if possible.- threshold
a threshold value for node imbalance.
Value
For any internal node, the function nodeImb gives the number of tip descendants of each of the node's descending branches. The function nodeImbFrac returns the fraction of internal nodes where the difference between these numbers is greater than or equal to the threshold.
See also
Examples
## Find the fraction of internal nodes with an imbalance of 5 or more,
## in a random tree with 20 tips:
tree <- rtree(20)
plot(tree)
nodeImbFrac(tree,threshold=5)
#> [1] 0.05263158