Question

I have a list x here:

I want to show the relationship between the elements like this:

Can anyone tell me how to do this in R?
Thank you very much!

Answer 1

First, build a matrix of all pairs from your original list:

L <- list(c("John", "Mary", "Jack"), c("John", "Wendy"), c("Mary", "Wendy"))
x <- matrix(unlist(lapply(L, combn, 2, simplify = FALSE)), ncol = 2)

Then, use one of the methods shown here: Pairwise interaction matrix in R. I like the one using graph theory tools 🙂

library(igraph)
g <- graph.edgelist(x, directed = FALSE)
get.adjacency(g)

#       John Jack Mary Wendy
# John     0    1    1     1
# Jack     1    0    1     0
# Mary     1    1    0     1
# Wendy    1    0    1     0