R/itemset.R

In gaiac/TFARM: Transcription Factors Association Rules Miner

#' Builds the itemset in the left-hand-side of an association rule.
#'
#' The function is used in the construction of the left-hand-side of association
#' rules to search for a rule of interest.
#'

#' @param items a string vector.
#' @return Itemset of the left-hand-side of a searched rule, with the items
#' in \code{items}.
#' @export
#'
#' @examples
#' itemset(c('TAF1=1','EP300=1'))
#' # the output is: 'TAF1=1,EP300=1'


itemset <- function(items) {
    itemset.0 <- paste("{", items[1], sep = "")
    if (length(items) != 1) {
        tails <- tail(items, -1)
        for (i in 1:length(tails)) {
            itemset.0 <- paste(itemset.0, tails[i], sep = ",")
        }
        itemset.1 <- paste(itemset.0, "}", sep = "")
        return(itemset.1)
    } else {
        itemset.2 <- paste(itemset.0, "}", sep = "")
        return(itemset.2)
    }
}