DiagrammeR (version 1.0.9)

mutate_edge_attrs: Mutate a set of edge attribute values

Description

Within a graph's internal edge data frame (edf), mutate numeric edge attribute values using one or more expressions.

Usage

mutate_edge_attrs(graph, ...)

Value

A graph object of class dgr_graph.

Arguments

graph

A graph object of class dgr_graph.

...

Expressions used for the mutation of edge attributes. LHS of each expression is either an existing or new edge attribute name. The RHS can consist of any valid R code that uses edge attributes as variables. Expressions are evaluated in the order provided, so, edge attributes created or modified are ready to use in subsequent expressions.

See Also

Other Edge creation and removal: add_edge_clone(), add_edge_df(), add_edges_from_table(), add_edges_w_string(), add_edge(), add_forward_edges_ws(), add_reverse_edges_ws(), copy_edge_attrs(), create_edge_df(), delete_edges_ws(), delete_edge(), delete_loop_edges_ws(), drop_edge_attrs(), edge_data(), join_edge_attrs(), mutate_edge_attrs_ws(), recode_edge_attrs(), rename_edge_attrs(), rescale_edge_attrs(), rev_edge_dir_ws(), rev_edge_dir(), set_edge_attr_to_display(), set_edge_attrs_ws(), set_edge_attrs()

Examples

# Create a graph with 3 edges
graph <-
  create_graph() %>%
  add_path(n = 4) %>%
  set_edge_attrs(
    edge_attr = width,
    values = c(3.4, 2.3, 7.2))

# Get the graph's internal edf
# to show which edge attributes
# are available
graph %>% get_edge_df()

# Mutate the `width` edge
# attribute, dividing each
# value by 2
graph <-
  graph %>%
  mutate_edge_attrs(
    width = width / 2)

# Get the graph's internal
# edf to show that the edge
# attribute `width` had its
# values changed
graph %>% get_edge_df()

# Create a new edge attribute,
# called `length`, that is the
# log of values in `width` plus
# 2 (and, also, round all values
# to 2 decimal places)
graph <-
  graph %>%
  mutate_edge_attrs(
    length = (log(width) + 2) %>%
               round(2))

# Get the graph's internal edf
# to show that the edge attribute
# values had been mutated
graph %>% get_edge_df()

# Create a new edge attribute
# called `area`, which is the
# product of the `width` and
# `length` attributes
graph <-
  graph %>%
  mutate_edge_attrs(
    area = width * length)

# Get the graph's internal edf
# to show that the edge attribute
# values had been multiplied
# together (with new attr `area`)
graph %>% get_edge_df()