SL.extraction: Extract self-loops form given network
In shp2graph: Convert a 'SpatialLinesDataFrame' -Class Object to an 'igraph'-Class Object

SL.extraction

R Documentation

Extract self-loops form given network

A function to extract self-loops away in given network.

SL.extraction(nodelist, edgelist, eadf=NULL,Directed=F, DegreeL=NULL, 
              InDegreeL=NULL, OutDegreeL=NULL,Nexception=NULL,Eexception=NULL)

`nodelist`	A “nodelist” object;
`edgelist`	An “edgelist” object
`eadf`	A data frame of attributes corresponding to all the edges;
`Directed`	TRUE if edges are directed, FALSE otherwise;
`DegreeL`	An integer vector of degrees for each node in the given “nodelist”, and it could be ignored if edges are directed
`InDegreeL`	An integer vector of In-degrees for each node in the given “nodelist”, and it could be ignored if edges are undirected
`OutDegreeL`	An integer vector of Out-degrees for each node in the given “nodelist”, and it could be ignored if edges are undirected
`Nexception`	A vector of node IDs concerned as exceptions, and all the edges with these nodes included won't be processed;
`Eexception`	A vector of edge IDs concerned as exceptions, and all these edges won't be processed;

Two types of list returned for undirected and directed edges, respectively:

For “undirected” edges:

`newNodelist`	New node list with self-loops removed;
`newEdgelist`	New edge list with self-loops removed;
`newEadf`	New attribute data frame for the returned edgelist;
`DegreeL`	New degree vector cooresponding to the newly returned node list;

For “directed” network:

`newNodelist`	New node list with self-loops removed;
`newEdgelist`	New edgelist with self-loops removed;
`newEadf`	Data frame of attributes for the newly returned edge list;
`InDegreeL`	New In-degree vector cooresponding to the newly returned node list;
`OutDegreeL`	New Out-degree vector cooresponding to the newly returned node list;

An edge is recognised as a structure of self-loop when it starts and ends at the same point (location).