R/multiplot.R

In Farabell/MarIOGraphing: Graphing functions for MarIO data

#'Multiplot Function
#'@author Kristen Rodriguez
#'@param x A df
#'@return multiple plots arranged in grid
#'@description This function allows creation of multiple ggplot objects
#'displayed in a single plot
#'@examples
#'multiplot(s.YI1, s.YI2, s.YI4, s.VD4, s.CM, s.DP1,cols=3)
#'@import grid
#'@export

multiplot <- function(..., plotlist=NULL, file, cols=1, layout=NULL){
  library(grid)

  # Make a list from the ... arguments and plotlist
  plots <- c(list(...), plotlist)

  numPlots = length(plots)

  # If layout is NULL, then use 'cols' to determine layout
  if (is.null(layout)) {
    # Make the panel
    # ncol: Number of columns of plots
    # nrow: Number of rows needed, calculated from # of cols
    layout <- matrix(seq(1, cols * ceiling(numPlots/cols)),
                     ncol = cols, nrow = ceiling(numPlots/cols))
  }

  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))
    }
  }
}