R/MIGSAmultiplot.R

In MIGSA: Massive and Integrative Gene Set Analysis

setGeneric(name = "multiplot", def = function(plotlist, layout) {
  standardGeneric("multiplot")
})


# Multiple plot function
#
# ggplot objects must be passed in plotlist (as a list of ggplot objects)
# - layout: A matrix specifying the layout.
#
# If the layout is something like matrix(c(1,2,3,3), nrow=2, byrow=TRUE),
# then plot 1 will go in the upper left, 2 will go in the upper right, and
# 3 will go all the way across the bottom.
#
#' @importFrom grid grid.layout grid.newpage pushViewport viewport
setMethod(
  f = "multiplot",
  signature = c("list", "matrix"),
  definition = function(plotlist, layout) {
    plots <- c(plotlist)
    numPlots <- length(plots)

    if (numPlots == 1) {
      print(plots[[1]])
    } else {
      # Set up the page
      grid.newpage()
      pushViewport(viewport(layout = grid.layout(
        nrow(layout),
        ncol(layout)
      )))

      # Make each plot, in the correct location
      for (i in 1:numPlots) {
        # Get the i,j matrix positions of the regions that contain this
        # subplot
        matchidx <- as.data.frame(which(layout == i, arr.ind = TRUE))

        print(plots[[i]], vp = viewport(
          layout.pos.row = matchidx$row,
          layout.pos.col = matchidx$col
        ))
      }
    }
  }
)