DiagrammeR (version 0.9.0)

cache_edge_attrs_ws: Cache edge attributes (based on a selection of edges) in the graph

Description

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

Selections of edges can be performed using the following select_... functions: select_edges(), select_last_edge(), or select_edges_by_node_id(). Selections of edges can also be performed using the following traversal functions: trav_out_edge(), trav_in_edge(), or trav_both_edge().

Usage

cache_edge_attrs_ws(graph, edge_attr, mode = NULL)

Arguments

graph

a graph object of class dgr_graph.

edge_attr

the edge attribute from which to obtain values.

mode

a option to recast the returned vector of edge 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_edge_attrs(
    "value", rnorm(edge_count(.), 5, 2))

# Select all edges where the edge attribute
# `value` is less than 5
graph <-
  graph %>%
  select_edges("value < 5.0")

# Show the graph's edge data frame
graph %>% get_edge_df
#>   id from to  rel    value
#> 1  1    1  2 <NA> 5.090874
#> 2  2    2  3 <NA> 8.151559
#> 3  3    3  4 <NA> 5.436577
#> 4  4    4  5 <NA> 2.906929
#> 5  5    5  6 <NA> 4.422623

# Cache available values from the edge
# attribute `value` from the edges that
# are selected; ensure that the cached
# vector is numeric
graph <-
  graph %>%
  cache_edge_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
# }