How to get counts of intersections of six or more sets?

Question

I am running an analysis of a number of sets and I have been using the package VennDiagram, which has been working just fine, but it only handles up to 5 sets, and now it turns

Answer 1

OK, here's one way, assuming you represent sets as a list of vectors, and items to be searched in those sets also as vector:

# Example data format
sets <- list(v1 = 1:6, v2 = 1:8, v3 = 3:8)
items <- c(2:7)

# Search for items in each set
result <- data.frame(searched = items)
for (set in names(sets)) {
  result <- cbind(result, items %in% sets[[set]])
  names(result)[length(names(result))] <- set
}

# Count
library(plyr)
ddply(result, names(sets), function (i) {
  data.frame(count = nrow(i))
})

This gives you all combinations actually existing in the itemset:

     v1   v2    v3 count
1 FALSE TRUE  TRUE     1
2  TRUE TRUE FALSE     1
3  TRUE TRUE  TRUE     4