Mutate edge attribute values for a selection of edges
Within a graph's internal edge data frame (edf), mutate edge attribute values only for edges in a selection by using one or more expressions.
mutate_edge_attrs_ws(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. |
This function makes use of an active selection of edges (and the function
ending with _ws hints at this).
Selections of edges can be performed using the following selection
(select_*()) functions: select_edges(), select_last_edges_created(),
select_edges_by_edge_id(), or select_edges_by_node_id().
Selections of edges can also be performed using the following traversal
(trav_*()) functions: trav_out_edge(), trav_in_edge(),
trav_both_edge(), or trav_reverse_edge().
A graph object of class dgr_graph.
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(),
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()
# Create a graph with 3 edges
# and then select edge `1`
graph <-
create_graph() %>%
add_path(n = 4) %>%
set_edge_attrs(
edge_attr = width,
values = c(3.4, 2.3, 7.2)) %>%
select_edges(edges = 1)
# Get the graph's internal edf
# to show which edge attributes
# are available
graph %>% get_edge_df()
# Mutate the `width` edge
# attribute for the edges
# only in the active selection
# of edges (edge `1`); here,
# we divide each value in the
# selection by 2
graph <-
graph %>%
mutate_edge_attrs_ws(
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 %>%
clear_selection() %>%
select_edges(edges = 2:3) %>%
mutate_edge_attrs_ws(
length = (log(width) + 2) %>%
round(2))
# Get the graph's internal edf
# to show that the edge attribute
# values had been mutated only
# for edges `2` and `3` (since
# edge `1` is excluded, an NA
# value is applied)
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_ws(
area = width * length)
# Get the graph's internal edf
# to show that the edge attribute
# values had been multiplied
# together (with new attr `area`)
# for nodes `2` and `3`
graph %>% get_edge_df()
# We can invert the selection
# and mutate edge `1` several
# times to get an `area` value
# for that edge
graph <-
graph %>%
invert_selection() %>%
mutate_edge_attrs_ws(
length = (log(width) + 5) %>%
round(2),
area = width * length)
# Get the graph's internal edf
# to show that the 2 mutations
# occurred for edge `1`, yielding
# non-NA values for its edge
# attributes without changing
# those of the other edges
graph %>% get_edge_df()Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.