tmp-save/multiplot.R

In privefl/bigstatsr: Statistical Tools for Filebacked Big Matrices

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# Function taken from
# http://www.cookbook-r.com/Graphs/Multiple_graphs_on_one_page_%28ggplot2%29/

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# Multiple plot function
#
# ggplot objects can be passed in ...,
# or to plotlist (as a list of ggplot objects)
# - cols:   Number of columns in layout
# - layout: A matrix specifying the layout. If present, 'cols' is ignored.
#
# 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.
#
#' Multiple plot function
#'
#' Multiple ggplot function **taken from the
#' [Cookbook for R](https://goo.gl/ZV0qEW)**.
#'
#' @param ... Possibly pass ggplot objects here.
#' @param plotlist A list of ggplot objects.
#' @param cols The number of columns of the resulting multiplot.
#' @param layout Define a special layout as a matrix.
#' @param byrow If `layout` is `NULL`, plot by rows (the default).
#'
#' @export
#' @import grid
#'
#' @examples
#' set.seed(1)
#'
#' test <- big_attachExtdata()
#' svd <- big_SVD(test, big_scale(), k = 10)
#' multiplot(plot(svd), plot(svd, coeff = 1.2), cols = 2)
multiplot <- function(..., plotlist = NULL,
                      cols = 1,
                      byrow = TRUE,
                      layout = NULL) {

  # 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),
                     byrow = byrow)
  }

  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))
    }
  }
}

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