get_similar_nbrs {DiagrammeR} | R Documentation

## Get neighboring nodes based on node attribute similarity

### Description

With a graph a single node serving as the starting point, get those nodes in a potential neighborhood of nodes (adjacent to the starting node) that have a common or similar (within threshold values) node attribute to the starting node.

### Usage

    get_similar_nbrs(graph, node, node_attr, tol_abs = NULL, tol_pct = NULL)

### Arguments

`graph` | a graph object of class `dgr_graph`.
`node` | a single-length vector containing a node ID value.
`node_attr` | the name of the node attribute to use to compare with adjacent nodes.
`tol_abs` | if the values contained in the node attribute `node_attr` are numeric, one can optionally supply a numeric vector of length 2 that provides a lower and upper numeric bound as criteria for neighboring node similarity to the starting node.
`tol_pct` | if the values contained in the node attribute `node_attr` are numeric, one can optionally supply a numeric vector of length 2 that specifies lower and upper bounds as negative and positive percentage changes to the value of the starting node. These bounds serve as criteria for neighboring node similarity to the starting node.

### Value

a vector of node ID values.

### Examples

    # Getting similar neighbors can be done through
    # numerical comparisons; start with creating a
    # random, directed graph with 18 nodes and 22 edges
    graph <-
      create_random_graph(
        n = 18, m = 22,
        set_seed = 23)

    # The `create_random_graph()` function randomly
    # assigns numerical values to all nodes (as the
    # `value` attribute) from 0 to 10 and to 1 decimal
    # place. By starting with node (`8`), we can test
    # whether any nodes adjacent and beyond are
    # numerically equivalent in `value`
    graph %>%
      get_similar_nbrs(
        node = 8,
        node_attr = "value")
    #> [1] 7 10

    # We can also set a tolerance for ascribing
    # similarly by using either the `tol_abs` or
    # `tol_pct` arguments (the first applies absolute
    # lower and upper bounds from the value in the
    # starting node and the latter uses a percentage
    # difference to do the same); try setting `tol_abs`
    # with a fairly large range to determine if several
    # nodes can be selected
    graph %>%
      get_similar_nbrs(
        node = 8,
        node_attr = "value",
        tol_abs = c(3, 3))
    #> [1]  7  9 10 11 12

    # That resulted in a fairly large set of 5
    # neigboring nodes; For sake of example, setting the
    # range to be very large will effectively return all
    # nodes in the graph except for the starting node
    graph %>%
      get_similar_nbrs(
        node = 8,
        node_attr = "value",
        tol_abs = c(10, 10)) %>%
        length()
    #> [1] 13

[Package DiagrammeR version 0.9.2 Index]