# neighb: Neighborhood of an actor or group of actors In multiplex: Algebraic Tools for the Analysis of Multiple Social Networks

## Description

A function to find the neighborhood of an actor or group of actors with a customized distance.

## Usage

 `1` ```neighb(x, rs, type = c("und", "inn", "out"), k = 1, inclx = FALSE, expand) ```

## Arguments

 `x` the reference actor labeled in `rs` or a vector of several actors `rs` the relational system of the network `type` whether the network is undirected (default) `und`; directed with incoming node's ties `inn` to the the reference actor, or else with outgoing arcs `out` `k` the “distance” of the neighbor nodes to the reference actor (where `k=1` gives the adjacent nodes) `inclx` (logical) should the reference actor be included in the output? `expand` (optional and logical) should the output be given by `k` (it only makes sense when `k>1`)

## Details

The relational system serves to represent either the entire multiple network, or else just the relational bundles having a mutual or an asymmetric character. In this sense, this function detects the adjacent nodes to `x` according to the specified relational system, but as well the neighbours of the adjacent nodes with a customized length. Eventually, when the longest path or chain is reached, adding more value to `k` obviously will not produce more nodes in the graph system.

## Value

Depending on `expand`, either a vector or a list with the neighbour nodes to the reference actor(s).

## Note

In case that the reference actors are in different components of the network, the output does not discriminate this fact.

## Author(s)

Antonio Rivero Ostoic

`expos`, `rel.sys`, `bundles`
 ```1 2 3 4 5 6 7 8 9``` ```## Create the data: two binary relations among three elements arr <- round( replace( array( runif(18), c(3 ,3, 2) ), array( runif(18), c(3, 3, 2) ) > .9, 3 ) ) ## Determine the system of strong bonds rs <- rel.sys(arr, bonds = "strong") ## the inmediate neighbourhood of the first node neighb(1, rs) ```