DiagrammeR (version 0.9.2)

add_path: Add a path of nodes to the graph

Description

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

Usage

add_path(graph, n, type = NULL, label = TRUE, rel = NULL, ...)

Arguments

graph

a graph object of class dgr_graph.

n

the number of nodes comprising the path.

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 boolean 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 path.

...

optional node attributes supplied as vectors.

Value

a graph object of class dgr_graph.

Examples

# NOT RUN {
# Create a new graph and add
# 2 paths of varying lengths
graph <-
  create_graph() %>%
  add_path(
    n = 4,
    type = "path") %>%
  add_path(
    n = 5,
    type = "path")

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

# Attributes can be specified
# in extra arguments and these
# are applied in order; Usually
# these attributes are applied
# to nodes (e.g., `type` is a
# node attribute) but the `rel`
# attribute will apply to the
# edges
graph_w_attrs <-
  create_graph() %>%
  add_path(
    n = 6,
    label = c("one", "two",
              "three", "four",
              "five", "six"),
    type = c("a", "a",
             "b", "b",
             "c", "c"),
    value = c(1.2, 8.4,
              3.4, 5.2,
              6.1, 2.6),
    rel = "path")

# Get the graph's node data frame
get_node_df(graph_w_attrs)
#>   id type label value
#> 1  1    a   one   1.2
#> 2  2    a   two   8.4
#> 3  3    b three   3.4
#> 4  4    b  four   5.2
#> 5  5    c  five   6.1
#> 6  6    c   six   2.6

# Get the graph's edge data frame
get_edge_df(graph_w_attrs)
#>   id from to  rel
#> 1  1    1  2 path
#> 2  2    2  3 path
#> 3  3    3  4 path
#> 4  4    4  5 path
#> 5  5    5  6 path
#> 6  6    6  1 path
# }