library(igraph)
library(DiagrammeR)
library(DiagrammeRsvg)
library(rsvg)
cat("Attached packages:\n")
print(sub("package:", "", search()[grep("^package:", search())]))


# --- edges dataframe (your real one) ---
edges <- data.frame(
  from = c("A","A","B","C"),
  to   = c("B","C","D","E"),
  stringsAsFactors = FALSE
)

# --- build igraph ---
g <- graph_from_data_frame(edges, directed = TRUE)

# --- relabel vertices to numeric IDs (DiagrammeR-friendly), keep original as label ---
V(g)$label <- V(g)$name
V(g)$name  <- as.character(seq_len(vcount(g)))  # "1","2","3",...

# --- to DiagrammeR + Graphviz layout attributes ---
gr <- from_igraph(g)
gr$graph_attrs$layout  <- "dot"
gr$graph_attrs$rankdir <- "TB"

# --- export jpeg ---

export_graph(
  graph = g,
  file_name = "graph.pdf",
  file_type = "pdf"
)