Question

基于共享两个ggplot2图表之间的图例脚本（https://github.com/tidyverse/ggplot2/wiki/Share-a-legend-between-two-ggplot2-graphs）。我尝试将结果组合图保存为TIFF，但它不起作用，因为我得到一个白色图像，任何想法如何解决它？

脚本：

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


grid_arrange_shared_legend <- function(..., ncol = length(list(...)), nrow = 1, position = c("bottom", "right")) {

  plots <- list(...)
  position <- match.arg(position)
  g <- ggplotGrob(plots[[1]] + theme(legend.position = position))$grobs
  legend <- g[[which(sapply(g, function(x) x$name) == "guide-box")]]
  lheight <- sum(legend$height)
  lwidth <- sum(legend$width)
  gl <- lapply(plots, function(x) x + theme(legend.position="none"))
  gl <- c(gl, ncol = ncol, nrow = nrow)

  combined <- switch(position,
                     "bottom" = arrangeGrob(do.call(arrangeGrob, gl),
                                            legend,
                                            ncol = 1,
                                            heights = unit.c(unit(1, "npc") - lheight, lheight)),
                     "right" = arrangeGrob(do.call(arrangeGrob, gl),
                                           legend,
                                           ncol = 2,
                                           widths = unit.c(unit(1, "npc") - lwidth, lwidth)))
  grid.newpage()
  grid.draw(combined)

}


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)
cP<- grid_arrange_shared_legend(p1, p2, p3, p4, ncol = 4, nrow = 1)


ggsave ("E:/cP.tiff", cP, dpi=500)

Answer 1

您的grid_arrange_shared_legend功能无法返回任何内容。让它返回combined对象（gtable），它应该可以工作。

   return(combined)

保存共享图例ggplot2

1 个答案: