mpaR 0.4.0

Initial CRAN release.

Features

• Implements Main Path Analysis (MPA) as introduced by Hummon and Doreian (1989), computing traversal weights (SPC, SPLC, SPNP) for each edge of a directed acyclic graph (DAG) and extracting the global, local, and key-route main paths.
• check_dag() validates that a graph is acyclic and reports the back-edges responsible for any cycles.
• classify_nodes() labels vertices by role (source/terminal/user, or source/sink/user under the graph-theory convention).
• check_scale_free() fits a discrete power-law to the degree distribution and tests for scale-free behaviour.
• edge_weights() and node_weights() compute traversal weights at the edge and node level.
• Readers for Pajek (read_pajek()) and Gephi export (read_gephi_export(), supporting .gexf and .graphml) files.
• plot_mpa() visualizes main paths, with a scope argument for restricting the plot to a subgraph.
• Per-component path extraction for disconnected networks.
• Accepts igraph objects or edge-list data frames as input throughout.