共享图例 3x3 ggplots

Question

我需要一个带有共享图例的 3x3 ggplot。问答解决了 1x4 图（不是我需要的 3x3）的问题。我曾尝试根据需要修改函数，经过多次尝试，我必须承认 baptistes 函数远远超出了我的 R 知识范围。

这是一个 MWE，基于所引用问题中的相同示例（希望可以借用它）。

library(ggplot2)
library(grid)
library(gridExtra)

dsamp <- diamonds[sample(nrow(diamonds), 1000), ]
p1 <- qplot(carat, price, data=dsamp, colour=clarity)
p2 <- qplot(cut, price, data=dsamp, colour=clarity)
p3 <- qplot(color, price, data=dsamp, colour=clarity)
p4 <- qplot(depth, price, data=dsamp, colour=clarity)
p5 <- qplot(carat, price, data=dsamp, colour=clarity)
p6 <- qplot(cut, price, data=dsamp, colour=clarity)
p7 <- qplot(color, price, data=dsamp, colour=clarity)
p8 <- qplot(depth, price, data=dsamp, colour=clarity)
p9 <- qplot(carat, price, data=dsamp, colour=clarity)

grid_arrange_shared_legend <- function(..., layout = rbind(c(1,2,3,4), 
                                                           c(5,5,5,5))) {
  plots <- list(...)
  g <- ggplotGrob(plots[[1]] + theme(legend.position="bottom"))$grobs
  legend <- g[[which(sapply(g, function(x) x$name) == "guide-box")]]
  lheight <- sum(legend$height)
  gl <- lapply(plots, function(x) x + theme(legend.position="none"))
  grid.arrange(grobs = c(gl, list(legend)), layout_matrix = layout,
               heights = grid::unit.c(unit(1, "npc") - lheight, lheight))
}

grid_arrange_shared_legend(p1, p2, p3, p4)  # This works
grid_arrange_shared_legend(p1, p2, p3, p4, p5, p6, p7, p8, p9)  # This is what I need

这是我需要处理的示例中的最后一行。

Answer 1

看起来提供的示例代码仅适用于单行绘图。您可以将其更改为更贴心：

grid_arrange_shared_legend <- function(..., layout = rbind(c(1,2,3,4), 
                                                           c(5,5,5,5))) {
  plots <- list(...)
  g <- ggplotGrob(plots[[1]] + theme(legend.position="bottom"))$grobs
  legend <- g[[which(sapply(g, function(x) x$name) == "guide-box")]]
  lheight <- sum(legend$height)
  gl <- lapply(plots, function(x) x + theme(legend.position="none"))
  grid.arrange(grobs = c(gl, list(legend)), layout_matrix = layout,
               heights = grid::unit.c(rep((unit(1, "npc") - lheight)*(1/(nrow(layout)-1)),nrow(layout)-1), lheight))
} 

grid_arrange_shared_legend(p1, p2, p3, p4, p5, p6, p7, p8, p9, layout=rbind(1:3, 4:6, 7:9, rep(10,3)))

共享图例 3x3 ggplots

Shared legend 3x3 ggplots

r

legend

ggplot2

gridextra