stages_simplebhc {stagedtrees}

Backward hill-climbing for simple staged trees

Description

Greedy search of simple staged event trees with iterative joining of positions.

Usage

stages_simplebhc(
  object,
  score = function(x) {
     return(-BIC(x))
 },
  scope = NULL,
  max_iter = Inf,
  ignore = object$name_unobserved
)

Arguments

object

an object of class sevt with fitted probabilities and data, as returned by full or sevt_fit.

score

the score function to be maximized.

scope

names of variables that should be considered for the optimization.

max_iter

the maximum number of iterations per variable.

ignore

vector of stages which will be ignored and left untouched, by default the name of the unobserved stages stored in object$name_unobserved.

Details

This function is similar to the classical backward hill-climbing implemented in stages_bhc, but instead of joining stages it consider joining of positions via join_positions. Thus, the search is in the space of simple staged tree models if the initial stage tree is simple. See the references for additional details.

Value

an object of class sevt, the simple staged tree resulting from the search.

References

Leonelli M, Varando G. Structural Learning of Simple Staged Trees, arXiv preprint arXiv:2203.04390v1

See Also

join_positions() sevt_simplify()

Examples

mod <- stages_simplebhc(full(Titanic))
plot(mod)