Query the Probability of a Specific Pathway -> Next State

Returns the probability the fitted tree assigns to a given pathway / next-state pair. Two lookup modes:

• exact = TRUE: the pathway must appear as a node; otherwise returns NA.

• exact = FALSE (default): if the pathway is missing, falls back to the longest matching suffix that *is* in the tree (mirrors predict.transitiontrees()).

Usage

query_pathway(tree, pathway, next_state = NULL, exact = FALSE)

Arguments

tree

A transitiontrees.

pathway

Character. The conditioning pathway, either as a single arrow-notation string ("A -> B -> C") or as a character vector of states (c("A","B","C")).

next_state

Character. Next-state symbol to query, or NULL (default) to return the full conditional distribution.

exact

Logical. Default FALSE — fall back to longest matching suffix.

Value

If next_state is supplied, a numeric scalar. Otherwise a named numeric vector indexed by alphabet.

Examples

# \donttest{
set.seed(1)
m <- matrix(sample(c("A","B","C"), 200, TRUE), 20)
tr <- context_tree(m, max_depth = 2L, min_count = 3L)
query_pathway(tr, c("A","B"))
#>         A         B         C 
#> 0.5294118 0.2352941 0.2352941 
query_pathway(tr, "A -> B", next_state = "C")
#> [1] 0.2352941
# }