Connecting All Nodes Together on a Graph-CodePudding

I have the following network graph:

library(tidyverse)
library(igraph)


set.seed(123)
n=5
data = tibble(d = paste(1:n))

relations = data.frame(tibble(
  from = sample(data$d),
  to = lead(from, default=from[1]),
))

graph = graph_from_data_frame(relations, directed=T, vertices = data) 

V(graph)$color <- ifelse(data$d == relations$from[1], "red", "orange")

plot(graph, layout=layout.circle, edge.arrow.size = 0.2)

I want to connect each Node to every Node on this graph - I can do this manually by redefining the "relations" data frame:

relations_1 = data.frame("from" = c(1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5), "to" = c(2,3,4,5,1,3,4,5,1,2,4,5,1,2,3,5,1,2,3,4))

Then, I can re-run the network graph:

graph = graph_from_data_frame(relations_1, directed=T, vertices = data) 

V(graph)$color <- ifelse(data$d == relations_1$from[1], "red", "orange")

plot(graph, layout=layout.circle, edge.arrow.size = 0.2)

But would there have been a way to "automatically" connect all the points in the graph directly using the "relations" data frame without manually creating a new data frame "relations_1"? Could a single line (or a few lines) of code have been added that would have automatically taken the "relations" data frame and connected everything together?

Thank you!

CodePudding user response：

You could just update relations using complete, and than filter out the rows where from is equal to to, which gives arrows from a node to itself.

relations <- relations %>% 
  complete(from, to) %>% 
  dplyr::filter(from != to)

CodePudding user response：

An solution using igraph::make_full_graph:

relations %>%
  with(union(from,to)) %>%
  {
    G <- make_full_graph(length(.), directed = TRUE)
    V(G)$name <- .
    G
  }