Creating a "combination tree" in R with ggplot2

Question

I am interested in making a picture like this:

Basically, I would like to show all the combinations possible. I tried to do this with ggplot2, but I can't find an exact function that makes this tree.

Is there a straightforward way to do this?

I created some data like this:

var1 <- sample( LETTERS[1:5], 100, replace=TRUE, prob=c(0.2, 0.2, 0.2, 0.2, 0.2) )

var2 <- sample( LETTERS[6:7], 100, replace=TRUE, prob=c(0.5, 0.5) )

var3<- sample( LETTERS[8:11], 100, replace=TRUE, prob=c(0.1, 0.2, 0.65, 0.05) )

f <- data.frame(var1, var2, var3)

f$var1 = as.factor(f$var1)

f$var2 = as.factor(f$var2)

f$var3 = as.factor(f$var3)

I tried:

plot(f)

But this didn't work. Thanks!

Answer 1

The R-graph gallery gives us a really good starting point.

library(ggraph)
library(igraph)
library(tidyverse)

d1 <- data.frame(from="origin", to=LETTERS[1:5])
d2 <- data.frame(from=rep(d1$to, each=2), to=paste(LETTERS[6:7], 1:10, sep="_"))
d3 <- data.frame(from=rep(d2$to, each=3), to=paste(LETTERS[8:10], 1:30, sep="_"))
edges <- do.call(rbind, list(d1, d2, d3))

mygraph <- graph_from_data_frame(edges)

# Basic tree
ggraph(mygraph, layout = 'dendrogram', circular = FALSE) + 
    geom_edge_diagonal() +
    geom_node_point() +
    geom_node_text(aes(label = c("origin", gsub("[0-9]|_","",edges$to))), repel = TRUE, colour = 'blue') +
    theme_void()