Symmetric KL Distance Between Two context trees

Bare-metal scalar: a count-weighted average of per-context symmetric Kullback-Leibler divergence over the union of pathways present in either tree. No null distribution.

Usage

tree_distance(tree_a, tree_b, symmetric = TRUE)

Arguments

tree_a, tree_b

context trees with matching alphabets.

symmetric

Logical. TRUE (default) returns \(0.5(D_{KL}(A\|B) + D_{KL}(B\|A))\); FALSE returns \(D_{KL}(A\|B)\) only.

Value

Numeric scalar.

Examples

# \donttest{
set.seed(1)
m1 <- matrix(sample(c("A","B","C"), 200, TRUE), 20)
m2 <- matrix(sample(c("A","B","C"), 200, TRUE), 20)
tr1 <- context_tree(m1, max_depth = 2L, min_count = 3L)
tr2 <- context_tree(m2, max_depth = 2L, min_count = 3L)
tree_distance(tr1, tr2)
#> [1] 0.05750785
# }