R: Simple graph operations

Simple Graph Operations {ggm} | R Documentation

## Simple graph operations

### Description

Finds the boundary, children, parents of a subset of nodes of a graph.

### Usage

    bd(nn, amat)
    ch(nn, amat)
    pa(nn, amat)

### Arguments

`nn` | a vector of nodes. It may either a numeric vector, or a character vector. If it is character vector must be a subset of the `rownames` of the edge matrix.
`amat` | a square matrix with dimnames specifying the adjacency matrix of the graph

### Details

For definitions of the operators see Lauritzen (1996).

### Value

The operators return a character vector specifying the boundary or the children or the parents of nodes `nn` in the graph. This is a numeric or a character vector depending on the mode of `nn`.

### Author(s)

Giovanni M. Marchetti

### References

Lauritzen, S. (1996). Graphical models. Oxford: Clarendon Press.

### See Also

`UG`, `DAG`

### Examples

    ## find boundary of a subset of nodes of a DAG
    G <- DAG(y ~ x+b+a, b~a, x~a)
    bd("b", G)
    bd(c("b", "x"), G)
    bd("x", G)
    bd(c("x","b"), G)
    ## find boundary of a subset of nodes of an UG
    G <- UG(~ y*x*z + z*h*v)
    bd("z", G)
    bd(c("y", "x"), G)
    bd("v", G)
    bd(c("x","v"), G)
    ## children of a subset of nodes of a DAG
    G <- DAG(y ~ x+b+a, b~a, x~a)
    ch("b", G)
    ch(c("b", "x"), G)
    ch("x", G)
    ch(c("a","x"), G)
    ## parents of a subset of nodes of a DAG
    pa("b", G)
    pa(c("b", "x"), G)
    pa("x", G)
    pa(c("x","b"), G)

[Package ggm version 2.3 Index]