Add a star of nodes to the graph — add

With a graph object of class dgr_graph, add a node star to the graph.

Usage

add_star(
  graph,
  n,
  type = NULL,
  label = TRUE,
  rel = NULL,
  node_aes = NULL,
  edge_aes = NULL,
  node_data = NULL,
  edge_data = NULL
)

Arguments

graph: A graph object of class dgr_graph.
n: The number of nodes comprising the star. The first node will be the center of the star.
type: An optional string that describes the entity type for the nodes to be added.
label: Either a vector object of length n that provides optional labels for the new nodes, or, a logical value where setting to TRUE ascribes node IDs to the label and FALSE yields a blank label.
rel: An optional string for providing a relationship label to all new edges created in the node star.
node_aes: An optional list of named vectors comprising node aesthetic attributes. The helper function node_aes() is strongly recommended for use here as it contains arguments for each of the accepted node aesthetic attributes (e.g., shape, style, color, fillcolor).
edge_aes: An optional list of named vectors comprising edge aesthetic attributes. The helper function edge_aes() is strongly recommended for use here as it contains arguments for each of the accepted edge aesthetic attributes (e.g., shape, style, penwidth, color).
node_data: An optional list of named vectors comprising node data attributes. The helper function node_data() is strongly recommended for use here as it helps bind data specifically to the created nodes.
edge_data: An optional list of named vectors comprising edge data attributes. The helper function edge_data() is strongly recommended for use here as it helps bind data specifically to the created edges.

Value

A graph object of class dgr_graph.

Examples

# Create a new graph and add 2
# stars of varying numbers of nodes
graph <-
  create_graph() %>%
  add_star(
    n = 4,
    type = "four_star") %>%
  add_star(
    n = 5,
    type = "five_star")

# Get node information from this graph
graph %>% get_node_info()
#>   id      type label deg indeg outdeg loops
#> 1  1 four_star     1   3     0      3     0
#> 2  2 four_star     2   1     1      0     0
#> 3  3 four_star     3   1     1      0     0
#> 4  4 four_star     4   1     1      0     0
#> 5  5 five_star     5   4     0      4     0
#> 6  6 five_star     6   1     1      0     0
#> 7  7 five_star     7   1     1      0     0
#> 8  8 five_star     8   1     1      0     0
#> 9  9 five_star     9   1     1      0     0

# Node and edge aesthetic and data
# attributes can be specified in
# the `node_aes`, `edge_aes`,
# `node_data`, and `edge_data`
# arguments

suppressWarnings(RNGversion("3.5.0"))
set.seed(23)

graph_w_attrs <-
  create_graph() %>%
  add_star(
    n = 4,
    label = c(
      "one", "two",
      "three", "four"),
    type = c(
      "a", "a", "b", "b"),
    rel = "A",
    node_aes = node_aes(
      fillcolor = "steelblue"),
    edge_aes = edge_aes(
      color = "red",
      penwidth = 1.2),
    node_data = node_data(
      value = c(
        1.6, 2.8, 3.4, 8.3)),
    edge_data = edge_data(
      value =
        rnorm(
          n = 3,
          mean = 5.0,
          sd = 1.0)))

# Get the graph's node data frame
graph_w_attrs %>% get_node_df()
#>   id type label fillcolor value
#> 1  1    a   one steelblue   1.6
#> 2  2    a   two steelblue   2.8
#> 3  3    b three steelblue   3.4
#> 4  4    b  four steelblue   8.3

# Get the graph's edge data frame
graph_w_attrs %>% get_edge_df()
#>   id from to rel penwidth color    value
#> 1  1    1  2   A      1.2   red 5.996605
#> 2  2    1  3   A      1.2   red 6.107490
#> 3  3    1  4   A      1.2   red 4.721914