cograph (version 2.7.2)

filter_nodes: Filter Nodes by Metadata or Centrality

Description

Filter nodes using dplyr-style expressions on any node column or centrality measure. Returns a cograph_network object by default (universal format), or optionally a matrix, igraph, or statnet network object when keep_format = TRUE and the input used one of those formats.

Usage

filter_nodes(
  x,
  ...,
  keep_edges = c("internal", "none"),
  keep_format = FALSE,
  directed = NULL,
  .keep_edges = NULL
)
subset_nodes(
  x,
  ...,
  keep_edges = c("internal", "none"),
  keep_format = FALSE,
  directed = NULL,
  .keep_edges = NULL
)

Value

A cograph_network object with filtered nodes. If keep_format = TRUE, matrix, igraph, and statnet network inputs are converted back to that type.

Arguments

x

Network input: cograph_network, matrix, igraph, network, or tna object.

...

Filter expressions using any node column or centrality measure. Available variables include:

Node columns

All columns in the nodes dataframe: id, label, name, x, y, inits, color, plus any custom

Centrality measures

degree, indegree, outdegree, strength, instrength, outstrength, betweenness, closeness, eigenvector, pagerank, hub, authority, coreness. Any other measure centrality() computes can be named too; see list_centralities().

Structural context and predicates

The same vocabulary select_nodes() documents, for example component, component_size, k_core, is_isolated, is_cut, local_transitivity.

Examples: degree >= 3, label %in% c("A", "B"), pagerank > 0.1 & degree >= 2.

On a network with negative edge weights, betweenness, closeness and pagerank are undefined: they return NA with a cograph_negative_weights warning.

keep_edges

How to handle edges. One of:

"internal"

(default) Keep only edges between remaining nodes

"none"

Remove all edges

keep_format

Logical. If TRUE, matrix, igraph, and statnet network inputs are returned in that format. Default FALSE returns cograph_network (universal format).

directed

Logical or NULL. If NULL (default), auto-detect from matrix symmetry. Set TRUE to force directed, FALSE to force undirected. Only used for non-cograph_network inputs.

.keep_edges

Deprecated. Use keep_edges.

See Also

filter_edges, splot, subset_nodes

Examples

adj <- matrix(c(0, .5, .8, 0, .5, 0, .3, .6,
                .8, .3, 0, .4, 0, .6, .4, 0), 4, 4, byrow = TRUE)
rownames(adj) <- colnames(adj) <- c("A", "B", "C", "D")

# Keep only high-degree nodes
filter_nodes(adj, degree >= 3)

# Filter by label, combined with degree
filter_nodes(adj, degree >= 2 & label != "D")