r - 如何将空图添加到多图？

Question

假设您要创建一个如下图所示的图形。

我想使用基于ggplot2. 如何添加空图以使用多图获得三角形输出？

MWE如下：

library(ggplot2)

# Multiplot function from http://www.cookbook-r.com/Graphs/Multiple_graphs_on_one_page_(ggplot2)/
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))
    }
  }
}

# Example plot
p <- ggplot(data = mtcars, aes(x=wt, y=mpg)) + geom_point()

multiplot(p,p,p,p,p,p,p,p,p,cols=3)  

这产生

标签： rggplot2

Answer 1

或者， grid.arrange() 可以使用布局，

m = matrix(NA, 3, 3)
m[upper.tri(m, TRUE)] = 1:6
lp = replicate(6, ggplot(), FALSE)
gridExtra::grid.arrange(grobs = lp, layout_matrix = m)