PN.amalgamation {shp2graph}

Amalgamate edges connected by a pseudo-node

Description

A function to amalgamate edges connected by a pseudo-node.

Usage

PN.amalgamation(nodelist, edgelist, eadf=NULL, ea.prop=NULL, Directed=F, 
                DegreeL=NULL, InDegreeL=NULL, OutDegreeL=NULL,Nexception=NULL,
                Eexception=NULL)

Arguments

nodelist

A “nodelist” object;

edgelist

An “edgelist” object

eadf

A data frame of attributes corresponding to all the edges;

ea.prop

A vector (of the length equalling to the number of edge attributes in “eadf”) with values of 1, 2, 3 or 4, and each specific value represent a function to assign the attributes of the edited edges, see also Redef.functions:

1->sum(v)

2->min(v)

3->max(v)

4->mean(v)

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;

Value

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

For “undirected” edges:

newNodelist

New node list with pseudo-nodes removed;

newEdgelist

New edge list with pseudo-nodes 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 pseudo-nodes removed;

newEdgelist

New edgelist with pseudo-nodes 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;

Note

Node in a directed network is recognised a a pseudo-node with in-degree and out-degree equalling to 1; while it could be a pseudo-node with degree equalling to 2 in a undirected network.

Author(s)

Binbin Lu [e-mail]

See Also

SL.extraction, ME.simplification

Examples

data(ORN)
rtNEL<-readshpnw(ORN.nt, ELComputed=TRUE)
res.sl<-SL.extraction(rtNEL[[2]],rtNEL[[3]])
res.me<-ME.simplification(res.sl[[1]],res.sl[[2]],DegreeL=res.sl[[4]]) 
res.pn<-PN.amalgamation(res.me[[1]],res.me[[2]],DegreeL=res.me[[4]])
ptcoords<-Nodes.coordinates(res.pn[[1]])
#plot(ORN.nt)
#points(ptcoords, col="green")
#plot(ORN.nt)
#points(Nodes.coordinates(rtNEL[[2]]), col="red")