The state-to-state weight matrix behind a ts_tna()-family model: transition
probabilities for ts_tna(), counts for ts_ftna(), and so on. Without this
method as.matrix() falls through to the default, which coerces the object's
component list rather than its network.
Usage
# S3 method for class 'ts_tna'
as.matrix(x, rownames.force = NA, ...)