Returns height of a SEM Tree, which equals to the length of the longest path from root to a terminal node.
getHeight(tree)Example: A SEM tree with only the root node has depth 0. A SEM tree with one decision node has depth 1.
Brandmaier, A.M., Oertzen, T. v., McArdle, J.J., & Lindenberger, U. (2013). Structural equation model trees. Psychological Methods, 18(1), 71-86.