Compute Shortest Path Distances

Computes shortest path distances between nodes in a network. Supports all-pairs, single-source, and point-to-point queries.

Usage

shortest_paths(x, from = NULL, to = NULL, weights = NULL, directed = NULL, ...)

Arguments

x

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

from

Character or numeric node identifier(s) for the source. If NULL (default), compute distances from all nodes.

to

Character or numeric node identifier(s) for the target. If NULL (default), compute distances to all nodes.

weights

Edge weight handling: NULL (default) auto-detects from edge attributes, NA forces unweighted distances, or a numeric vector of custom weights.

directed

Logical or NULL. If NULL (default), auto-detect from matrix symmetry. Set TRUE to force directed, FALSE to force undirected.

...

Not used. Any argument supplied here raises an "unused argument" error.

Value

Depends on the query:

• If both from and to are NULL: a full distance matrix (all pairs)

• If from is a single node and to is NULL: a named numeric vector of distances from that node to all others

• If from is multiple nodes and to is NULL: a matrix with rows for each source

• If both from and to are single nodes: a single numeric value

• Otherwise: a matrix of distances between the specified node sets

Details

Distances are computed with igraph::distances(). For weighted networks, edge weights are used as distances by default. With weights = NA, every edge has unit distance.

igraph also exports a shortest_paths() with a different signature and return value; when both packages are attached, qualify the call as cograph::shortest_paths().

See also

k_shortest_paths, network_summary

Examples

cograph::shortest_paths(regulation_net, from = "Plan")
#>    Explore       Plan    Monitor      Adapt    Reflect    Discuss Synthesize 
#>       0.34       0.00       0.13       0.29       0.56       0.40       0.46 
#>   Evaluate     Create      Share 
#>       0.49       0.20       0.36