find_cutoff: Find node cutoff strength

In elizagrames/litsearchr: Automated Search Term Selection and Search Strategy for Systematic Reviews

Description

Find the minimum node strength to use as a cutoff point for important nodes.

Usage

find_cutoff(
  graph,
  method = c("changepoint", "cumulative"),
  percent = 0.8,
  knot_num = 3,
  imp_method = "strength"
)

Arguments

graph	An igraph graph object
method	the cutoff method to use, either "changepoint" or "cumulative"
percent	if using method cumulative, the total percent of node strength to capture
knot_num	if using method changepoint, the number of knots to identify
imp_method	a character specifying the importance measurement to be used; takes arguments of "strength", "eigencentrality", "alpha", "betweenness", "hub" or "power"

Details

The changepoint fit finds tipping points in the ranked order of node strengths to use as cutoffs. The cumulative fit option finds the node strength cutoff point at which a certain percent of the total strength of the graph is captured (e.g. the fewest nodes that contain 80% of the total strength).

Value

a vector of suggested node cutoff strengths

Examples

dfm <- create_dfm(
  elements = c(
    "Cross-scale occupancy dynamics of a postfire specialist
    in response to variation across a fire regime",
    "Variation in home-range size of Black-backed Woodpeckers",
    "Black-backed woodpecker occupancy in burned and beetle-killed forests"
  ),
  features = c("occupancy", "variation", "black-backed woodpecker", "burn")
)

my_network <- create_network(search_dfm = as.matrix(dfm),
                             min_studies = 1,
                             min_occ = 1)

find_cutoff(my_network,
            method = "cumulative",
            percent = .9)

find_cutoff(my_network,
            method = "changepoint",
            knot_num = 3)

elizagrames/litsearchr documentation built on April 14, 2021, 3:42 p.m.