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Add a node to an existing graph object

Source: R/add_node.R
add_node.Rd

With a graph object of class dgr_graph, add a new node to the graph. One can optionally provide node attributes for the created node. There is also the option to create edges to and from existing nodes in the graph. Because new edges can also be created through this function, there is the possibility to set edge attributes for any new graph edges.

Usage

add_node(
  graph,
  type = NULL,
  label = NULL,
  from = NULL,
  to = NULL,
  node_aes = NULL,
  edge_aes = NULL,
  node_data = NULL,
  edge_data = NULL
)

Arguments

graph

A graph object of class dgr_graph.

type

An optional character object that acts as a group identifier for the node to be added.

label

An optional character object that describes the node.

from

An optional vector containing node IDs from which edges will be directed to the new node.

to

An optional vector containing node IDs to which edges will be directed from the new node.

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.

See also

Other node creation and removal: add_n_node_clones(), add_n_nodes(), add_n_nodes_ws(), add_node_clones_ws(), add_node_df(), add_nodes_from_df_cols(), add_nodes_from_table(), colorize_node_attrs(), copy_node_attrs(), create_node_df(), delete_node(), delete_nodes_ws(), drop_node_attrs(), join_node_attrs(), layout_nodes_w_string(), mutate_node_attrs(), mutate_node_attrs_ws(), node_data(), recode_node_attrs(), rename_node_attrs(), rescale_node_attrs(), set_node_attr_to_display(), set_node_attr_w_fcn(), set_node_attrs(), set_node_attrs_ws(), set_node_position()

Examples

# Create an empty graph and add 2 nodes by using
# the `add_node()` function twice
graph <-
  create_graph() %>%
  add_node() %>%
  add_node()

# Get a count of all nodes
# in the graph
graph %>% count_nodes()
#> [1] 2

# The nodes added were given
# ID values `1` and `2`; obtain
# the graph's node IDs
graph %>% get_node_ids()
#> [1] 1 2

# Add a node with a `type`
# value defined
graph <-
  graph %>%
  add_node(type = "person")

# View the graph's internal
# node data frame (ndf)
graph %>% get_node_df()
#>   id   type label
#> 1  1   <NA>  <NA>
#> 2  2   <NA>  <NA>
#> 3  3 person  <NA>