# Select edges in a graph using node ID values

Source:`R/select_edges_by_node_id.R`

`select_edges_by_node_id.Rd`

Select edges in a graph object of class `dgr_graph`

using node ID values. All
edges associated with the provided nodes will be included in the selection.

## Arguments

- graph
A graph object of class

`dgr_graph`

.- nodes
A vector of node IDs for the selection of edges present in the graph.

- set_op
The set operation to perform upon consecutive selections of graph edges This can either be as a

`union`

(the default), as an intersection of selections with`intersect`

, or, as a`difference`

on the previous selection, if it exists.

## Examples

```
# Create a graph with 5 nodes
graph <-
create_graph() %>%
add_path(n = 5)
# Create a graph selection by selecting edges
# associated with nodes `1` and `2`
graph <-
graph %>%
select_edges_by_node_id(
nodes = 1:2)
# Get the selection of edges
graph %>% get_selection()
#> [1] 1 2
# Perform another selection of edges, with nodes
# `1`, `2`, and `4`
graph <-
graph %>%
clear_selection() %>%
select_edges_by_node_id(
nodes = c(1, 2, 4))
# Get the selection of edges
graph %>% get_selection()
#> [1] 1 2 3 4
# Get a fraction of the edges selected over all
# the edges in the graph
graph %>%
{
l <- get_selection(.) %>%
length(.)
e <- count_edges(.)
l/e
}
#> [1] 1
```