| mutate_edge_attrs {DiagrammeR} | R Documentation |
Within a graph's internal edge data frame (edf), mutate numeric edge attribute values using one or more expressions.
mutate_edge_attrs(graph, ...)
graph |
a graph object of class
|
... |
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. |
a graph object of class
dgr_graph.
# 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()