update_rollup: Update a rollup from a single leaf vertex

In rollupTree: Perform Recursive Computations

Update a rollup from a single leaf vertex

Description

update_rollup() performs a minimal update of a data set assuming a single leaf element property has changed. It performs updates along the path from that vertex to the root. There should be no difference in the output from calling rollup() again. update_rollup() is perhaps more efficient and useful in an interactive context.

Usage

update_rollup(tree, ds, vertex, update)

Arguments

tree	igraph directed graph that is a valid single-rooted in-tree and whose vertex names are keys from the data set
ds	data set to be updated; can be any object
vertex	The start vertex
update	function called at each vertex as update(ds, parent_key, child_keys)

Value

updated input data set

Examples

update_rollup(wbs_tree, wbs_table, igraph::V(wbs_tree)["3.2"],
  update = function(d, p, c) {
    if (length(c) > 0)
      d[d$id == p, c("work", "budget")] <-
        apply(d[is.element(d$id, c), c("work", "budget")], 2, sum)
      d
  }
)

rollupTree documentation built on Feb. 10, 2026, 5:09 p.m.