admixturegraph (version 1.0.2)

add_a_leaf: Adds a new leaf to a graph.

Description

Given an admixture graph, selects an edge and branches off a new edge ending at a new leaf.

Usage

add_a_leaf(graph, leaf_name, outgroup = "")

Arguments

graph

An admixture graph.

leaf_name

A name for the new leaf.

outgroup

An optional parameter for the preferred outgroup, which can be the new leaf.

Value

A list of graphs made by adding a new leaf to the input graph. The list has no duplicate elements.

See Also

all_graphs

fit_permutations_and_graphs

fit_graph_list

add_an_admixture

add_an_admixture2

make_an_outgroup

Examples

# Take a look at how much trees there are: 
leaves <- c("1", "2")
inner_nodes <- c("R")
edges <- parent_edges(c(edge("1", "R"), edge("2", "R")))
admixtures <- NULL
Lambda <- agraph(leaves, inner_nodes, edges, admixtures)
set <- list(Lambda)
for (i in seq(1, 6)) {
  new_set <- list()
  for (tree in set) {
    new_set <- c(new_set, add_a_leaf(tree, paste(i + 2)))
  }
  set <- new_set
  cat("There are ")
  cat(length(set))
  cat(" different trees with ")
  cat(i + 2)
  cat(" labeled leaves.")
  cat("\n")
}
# In general, there are 1*3*5*...*(2n - 5) different trees with n labeled leaves
# (A001147 in the online encyclopedia of integer sequences).
# Exhaustive search through the graph space is hard!