r マルチプロット

Posted 2021-05-24

MyMultiplot <-
  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
              ))
      }
    }
  }