combineNodes {graph}R Documentation

combineNodes

Description

A function to combine, or collapse, a specified set of nodes in a graph.

Usage

combineNodes(nodes, graph, newName)

Arguments

nodes A set of nodes that are to be collapsed.
graph The graph containing the nodes
newName The name for the new, collapsed node.

Details

The nodes specified are reduced to a single new node with label given by newName. The in and out edges of the set of nodes are all made into in and out edges for the new node.

Value

An new instance of a graph of the same class as graph is returned. This new graph has the specified nodes reduced to a single node.

Author(s)

R. Gentleman

See Also

inEdges, addNode

Examples

  V <- LETTERS[1:4]
  edL1 <- vector("list", length=4)
  names(edL1) <- V
  for(i in 1:4)
    edL1[[i]] <- list(edges=c(2,1,4,3)[i], weights=sqrt(i))
  gR <- new("graphNEL", nodes=V, edgeL=edL1, edgemode="directed")
  gR <- addNode("M", gR)
  gR <- addEdge("M", "A", gR, 1)
  gR <- addEdge("B", "D", gR, 1)
  gX <- combineNodes(c("B","D"), gR, "X")

[Package graph version 1.8.0 Index]