“edgelist” is an interchange structure of edges from a spatial network into an “igraph” object. It is a three-column matrix, of which each row is designed as [EdgeID,NodeID(from),NodeID(to)].
Both “nodelist” and “edgelist” are interchange structures of nodes and edges extracted from a spatial network in a “SpatialLines” or “SpatialLinesDataFrame” object. They are always concerned together, and returned by the function readshpnw as initial results for the following steps.