R: Remove Elements from a Network Object

deletion.methods {network} | R Documentation

## Remove Elements from a Network Object

### Description

`delete.edges` removes one or more edges (specified by their internal ID numbers) from a network; `delete.vertices` performs the same task for vertices (removing all associated edges in the process).

### Usage

    delete.edges(x, eid)
    delete.vertices(x, vid)

### Arguments

`x` | an object of class `network`.
`eid` | a vector of edge IDs.
`vid` | a vector of vertex IDs.

### Details

Note that an edge's ID number corresponds to its order within `x$mel`. To determine edge IDs, see `get.edgeIDs`. Likewise, vertex ID numbers reflect the order with which vertices are listed internally (e.g., the order of `x$oel` and `x$iel`, or that used by `as.matrix.network.adjacency`). When vertices are removed from a network, all edges having those vertices as endpoints are removed as well. When edges are removed, the remaining edge ids are NOT permuted and `NULL` elements will be left on the list of edges, which may complicate some functions that require eids (such as `set.edge.attribute`). The function `valid.eids` provides a means to determine the set of valid (non-NULL) edge ids.

Edges can also be added/removed via the extraction/replacement operators. See the associated man page for details.

### Value

Invisibly, a pointer to the updated network; these functions modify their arguments in place.

### Author(s)

Carter T. Butts buttsc@uci.edu

### References

Butts, C. T. (2008). “network: a Package for Managing Relational Data in R.” Journal of Statistical Software, 24(2). http://www.jstatsoft.org/v24/i02/

### See Also

`get.edgeIDs`, `network.extraction`, `valid.eids`

### Examples

    #Create a network with three edges
    m<-matrix(0,3,3)
    m[1,2]<-1; m[2,3]<-1; m[3,1]<-1
    g<-network(m)

    as.matrix.network(g)
    delete.edges(g,2)              #Remove an edge
    as.matrix.network(g)
    delete.vertices(g,2)           #Remove a vertex
    as.matrix.network(g)

    #Can also remove edges using extraction/replacement operators
    g<-network(m)
    g[1,2]<-0                      #Remove an edge
    g[,]
    g[,]<-0                        #Remove all edges
    g[,]

[Package network version 1.13.0.1 Index]