R/getNumNodes.R

In brandmaier/semtree: Recursive Partitioning for Structural Equation Models

#' Tree Size
#'
#' Counts the number of nodes in a tree.
#'
#'
#' @param tree A SEM tree object.
#' @author Andreas M. Brandmaier, John J. Prindle
#' @references Brandmaier, A.M., Oertzen, T. v., McArdle, J.J., & Lindenberger,
#' U. (2013). Structural equation model trees. \emph{Psychological Methods},
#' 18(1), 71-86.
getNumNodes <-
  function(tree) {
    if ((is.null(tree$left_child)) && (is.null(tree$right_child))) {
      return(1)
    }

    count <- 1

    if (tree$left_child$caption != "TERMINAL") {
      count <- count + getNumNodes(tree$left_child)
    } else {
      count <- count + 1
    }
    if (tree$right_child$caption != "TERMINAL") {
      count <- count + getNumNodes(tree$right_child)
    } else {
      count <- count + 1
    }

    return(count)
  }