remove_isolates: Remove Isolated Nodes

In cograph: Analysis and Visualization of Complex Networks

Remove Isolated Nodes

Description

Drops every node with no edges. Filtering edges deliberately keeps nodes (see filter_edges), so this is the explicit way to prune the isolates a filter left behind.

Usage

remove_isolates(x, keep_format = FALSE, directed = NULL)

Arguments

x	Network input: cograph_network, matrix, igraph, network, tna, or an edge-list data frame.
keep_format	Logical. If TRUE, matrix, igraph, statnet network and tna inputs are returned in that format. Default FALSE returns a cograph_network.
directed	Logical or NULL. If NULL (default), auto-detect.

Value

A cograph_network with the isolated nodes removed (or the input format when keep_format = TRUE). Node order is otherwise preserved and edge indices are remapped to the new node numbering.

See Also

filter_edges, split_components, filter_nodes

Examples

adj <- matrix(0, 4, 4, dimnames = list(LETTERS[1:4], LETTERS[1:4]))
adj["A", "B"] <- adj["B", "A"] <- 1

# C and D have no edges
remove_isolates(adj)

cograph documentation built on Sept. 30, 2026, 5:08 p.m.