Вы ищете что-то вроде этого:
library(igraph)
PubID <- c("169759","174843","174843","174843","174843","174843","171051","171051","171051","171719","171719","171719","169759","173847","173847")
Author <- c("ZJ","RA","DJ","JP","GS","Tv","MC","JR","CW","PB","MD","FO","FO","RA","DJ")
dt <- data.frame(Author,PubID)
levs <- unique(unlist(dt, use.names = FALSE))
adj <- table(lapply(dt, factor, levs))
g1 <- graph_from_adjacency_matrix( adj )
plot(g1)
Я создал матрицу смежности из ваших данных.