DiagrammeR (version 0.9.0)

cache_node_attrs_ws: Cache node attributes (based on a selection of nodes) in the graph

Description

From a graph object of class dgr_graph, get node attribute properties for nodes available in a selection and cache those values in the graph for later retrieval using get_cache.

Selections of nodes can be performed using the following select_... functions: select_nodes(), select_last_node(), select_nodes_by_degree(), select_nodes_by_id(), or select_nodes_in_neighborhood(). Selections of nodes can also be performed using the following traversal functions: (trav_...): trav_out(), trav_in(), trav_both(), trav_in_node(), trav_out_node().

Usage

cache_node_attrs_ws(graph, node_attr, mode = NULL)

Arguments

graph

a graph object of class dgr_graph.

node_attr

the node attribute from which to obtain values.

mode

a option to recast the returned vector of node attribute value as numeric or character.

Value

a graph object of class dgr_graph.

Examples

# NOT RUN {
# Set a seed
set.seed(23)

# Create a graph with 6 nodes and 5 edges
graph <-
  create_graph() %>%
  add_path(6) %>%
  set_node_attrs(
    "value", rnorm(node_count(.), 5, 2))

# Select all nodes where the node attribute `value`
# is less than 5
graph <-
  graph %>%
  select_nodes("value < 5.0")

# Show the graph's node data frame
graph %>% get_node_df
#>   id type label    value
#> 1  1 <NA>     1 5.090874
#> 2  2 <NA>     2 8.151559
#> 3  3 <NA>     3 5.436577
#> 4  4 <NA>     4 2.906929
#> 5  5 <NA>     5 4.422623
#> 6  6 <NA>     6 5.963101

# Cache available values from the node attribute
# `value` from the nodes that are selected; ensure
# that the cached vector is numeric
graph <-
  graph %>%
  cache_node_attrs_ws("value", "numeric")

# Get the cached vector and get its
# difference from 5
graph %>% get_cache() %>% {x <- .; 5 - x}
#> [1] 2.0930707 0.5773773
# }