igraph and data frames

igraph

library(igraph)
library(garphieldr)

graph <- make_ring(8, directed = TRUE)
V(graph)$group <- rep(c("A", "B"), 4)

project <- garphield_project(graph)
garphield(project)

round_trip <- as_igraph(project)

Vertex and edge attributes move into the project with direction and graph type intact. as_igraph() reconstructs the graph from the saved project.

Data frames

An edge table is enough:

edges <- data.frame(
  source = c("a", "b"),
  target = c("b", "c"),
  weight = c(1.2, 2.4)
)

project <- garphield_project(edges = edges)

Pass a node table when you have node attributes:

nodes <- data.frame(id = c("a", "b", "c"), label = c("A", "B", "C"))
project <- garphield_project(edges = edges, nodes = nodes)
tables <- as_data_frames(project)

Rename the structural columns with the constructor arguments. For parallel edges, pass edge_key = "key" and multigraph = TRUE.

Character, integer, double, and logical node identities remain distinct across the round trip.