R/pairVenn.R

In heuselm/mocode: Integrates MS-based-proteomics Data Analysis Code

#' pairVenn
#' @description Draws a pairwise Venn Diagram of two character vectors with overlap area corresponding to overlap size.
#' For the comparison of more sets, see compareSets function.
#' @param a Character vector a
#' @param b Character vector b
#' @param output character selection either "R" or "pdf"
#' @return paiwise Venn Diagram plot with areas corresponding to numbers
#' @import VennDiagram
#' @import gridExtra
#' @export
pairVenn <- function(a, b, output = "R"){
  require(gridExtra)
  require(VennDiagram)
  namea <- deparse(substitute(a))
  nameb <- deparse(substitute(b))
  ua <- unique(a)
  ub <- unique(b)
  mainlabel = paste("Pairwise Venn diagram of list", namea, "and", nameb)

  pairvenn <- draw.pairwise.venn(area1 = length(ua),
                                 area2 = length(ub),
                                 cross.area = length(intersect(ua, ub)),
                                 category = c(namea, nameb),
                                 cat.col = c("blue", "red"),
                                 col = c("blue", "red"),
                                 fill = c("blue", "red"),
                                 alpha = 0.2,
                                 margin = rep(0.05, 4))

  if (output == "R"){
    grid.arrange(gTree(children=pairvenn), top=mainlabel)
  }

  if (output == "pdf"){
    pdf(paste(mainlabel, ".pdf"))
    grid.arrange(gTree(children=pairvenn), top=mainlabel)
    dev.off()
  }
  
  anb <- intersect(ua, ub)
  aonly <- ua[!(ua %in% anb)]
  bonly <- ub[!(ub %in% anb)]
  groups <- list(aonly,
       anb,
       bonly)

}