Bridge profiles of a node across communities

Identifies which communities contribute most to the bridge role of a given node, by decomposing its bridge connectivity into community-specific contributions, excluding its own community when assigned. The function is designed as an interpretative companion to bridge_metrics() and bridge_metrics_excluded(), providing the components underlying the corresponding overall bridge indices.

Bridge connectivity is summarized using five complementary profiles: bridge strength, bridge EI1, bridge EI2, bridge closeness, and bridge betweenness.

For single layer fits (mixMN_fit), profiles are computed directly on the supplied fitted object.

For multilayer fits (multimixMN_fit), profiles are computed within the selected layer only, by applying the same single layer procedure to the corresponding intralayer fit stored in fit$layer_fits[[layer]].

Usage

find_bridge_communities(fit, node, layer = NULL)

Arguments

fit

An object of class mixMN_fit or multimixMN_fit.

node

Character scalar: node of interest.

layer

Character scalar giving the layer of interest for multimixMN_fit objects. Ignored for mixMN_fit objects.

Value

An object of class "bridge_profiles" (a named list) with the following components:

bridge_strength

Bridge strength. List with overall, the total value across all other communities, and by_comm, a tibble with community-specific contributions (community, sum_abs_w).

bridge_ei1

Bridge expected influence (order 1). List with overall and by_comm (community, sum_signed_w).

bridge_ei2

Bridge expected influence (order 2). List with overall and by_comm (community, sum_signed_w2).

bridge_closeness

Bridge closeness. List with overall and by_comm (community, inv_mean_dist).

bridge_betweenness

Bridge betweenness. List with overall and by_pair, a tibble with contributions by community pair (Ci, Cj, hits).

Details

Bridge profiles are computed using only connections from the focal node to nodes in communities different from its own. If the focal node is not assigned to any community, i.e. excluded, connections to all assigned nodes in communities are considered.

Bridge betweenness is computed by counting all shortest paths between pairs of nodes in different communities that pass through the focal node as an intermediate vertex. When multiple shortest paths exist, each path is counted separately.