Find the union and intersection of grouped variables-CodePudding

I have two vectors that are binned. Basically, I want a function to find the union and intersection of these two vectors (output). It seems there is no function that supports this feature. Any idea of how i can carry out the desired output vector?

example1 <- c("18--25", "26--30", "31--50", "51 ")
example2 <- c("18--23", "24--30", "31--65", "66 ")

output <- c("18--23", "24--25", "26--30", "31--50", "51--65", "66 ")

CodePudding user response：

We can remove duplicates and combine a sorted vector every 2 elements like this (R version 4.0 and later for pipe |>):

f <- function(x, y, sep, max){
  m <- paste0("\\", max)
  gsub(m, "", c(x, y)) |>
    strsplit(sep, fixed = T) |>
    unlist(use.names = F) |>
    sort() |>
    unique() |>
    as.numeric() |>
    (\(.) tapply(., gl(length(.), 2, length(.)), paste, collapse = sep, simplify = T))() |>
    (\(.) .[!is.na(.)])() |>
    as.character() |>
    (\(.) {.[length(.)] <- paste0(.[length(.)], max) ; .})()
}  

# for older R versions
f <- function(x, y, sep, max){
  x <- gsub(paste0("\\", max), "", c(x, y))
  x <- as.numeric(unique(sort(unlist(strsplit(x, sep, T), use.names = F))))
  x <- tapply(x, gl(length(x), 2L, length(x)), paste, collapse = sep, simplify = T)
  x <- as.character(x[!is.na(x)])
  x[length(x)] <- paste0(x[length(x)], max)
  x
}

f(example1, example2, "--", " ")
[1] "18--23" "24--25" "26--30" "31--50" "51--65" "66 "