Log10 x 轴在顶部，y 轴 geom_line

Question

我在 ggplot2 中创建了一个图形，如下所示：

depth = c(1.6,2.6,3.6, 4.6,5.6,6.6,7.6,8.6) 
ri <- c(0.790143779,1.485888068,2.682375391,1.728120227,0.948414515,71.43308158,4.416120653,0.125458801)
df = data.frame(depth,ri) 

library(ggplot2)

m <- qplot(ri, depth, data=df)
m + 
scale_x_log10("Richardson Number",breaks = c(0.1,0.25,0.5,1,5,10, 50)) + 
scale_y_reverse("Depth (m)")

这是输出：

我想要做的是在顶部设置 x 轴，并且还包括一个 geom_line，就像我在此处添加的（在 Paint 中手动添加的）。

我知道很难让 ggplot2 移动坐标轴，我试图在 ggvis 中重现此图，但我无法获得我需要的 log10 比例。有什么方法可以使用 R 来创建我想要的图形吗？

Answer 1

更新解决方案

从 ggplot 2.2.0 开始，可以在面板顶部绘制坐标轴（and/or 在面板右侧）

library(ggplot2)

depth = c(1.6,2.6,3.6, 4.6,5.6,6.6,7.6,8.6) 
ri <- c(0.790143779,1.485888068,2.682375391,1.728120227,0.948414515,71.43308158,4.416120653,0.125458801)
df = data.frame(depth,ri) 

m <- qplot(ri, depth, data=df) +
   scale_x_log10("Richardson Number",breaks = c(0.1,0.25,0.5,1,5,10, 50),
         position = "top") + 
   scale_y_reverse("Depth (m)")+
   geom_path()

原方案原方案，稍微更新到ggplot2.2.0版本后。

可以使用 gtable 函数移动坐标轴。改编@Walter 的回答 here 中的代码，基本思想是：获取轴（轴文本和刻度线）；反转轴文本和刻度线；在绘图面板正上方的 gtable 布局中添加一个新行；将修改后的轴插入新行。

library(ggplot2)
library(gtable)
library(grid)


depth = c(1.6,2.6,3.6, 4.6,5.6,6.6,7.6,8.6) 
ri <- c(0.790143779,1.485888068,2.682375391,1.728120227,0.948414515,71.43308158,4.416120653,0.125458801)
df = data.frame(depth,ri) 

m <- qplot(ri, depth, data=df) +
  scale_x_log10("Richardson Number",breaks = c(0.1,0.25,0.5,1,5,10, 50)) + 
  scale_y_reverse("Depth (m)")+
  geom_path()


# Get ggplot grob
g1 <- ggplotGrob(m)  

## Get the position of the plot panel in g1
pp <- c(subset(g1$layout, name == "panel", se = t:r))

# Title grobs have margins. 
# The margins need to be swapped.
# Function to swap margins - 
# taken from the cowplot package:
# https://github.com/wilkelab/cowplot/blob/master/R/switch_axis.R
vinvert_title_grob <- function(grob) {
  heights <- grob$heights
  grob$heights[1] <- heights[3]
  grob$heights[3] <- heights[1]
  grob$vp[[1]]$layout$heights[1] <- heights[3]
  grob$vp[[1]]$layout$heights[3] <- heights[1]

  grob$children[[1]]$hjust <- 1 - grob$children[[1]]$hjust 
  grob$children[[1]]$vjust <- 1 - grob$children[[1]]$vjust 
  grob$children[[1]]$y <- unit(1, "npc") - grob$children[[1]]$y
  grob
}

# Get  xlab  and swap margins
index <- which(g1$layout$name == "xlab-b")
xlab <- g1$grobs[[index]]
xlab <- vinvert_title_grob(xlab)

# Put xlab at the top of g1
g1 <- gtable_add_rows(g1, g1$heights[g1$layout[index, ]$t], pp$t-1)
g1 <- gtable_add_grob(g1, xlab, pp$t, pp$l, pp$t, pp$r, clip = "off", name="topxlab")

# Get x axis (axis line, tick marks and tick mark labels)
index <- which(g1$layout$name == "axis-b")
xaxis <- g1$grobs[[index]]

# Swap axis ticks and tick mark labels
ticks <- xaxis$children[[2]]
ticks$heights <- rev(ticks$heights)
ticks$grobs <- rev(ticks$grobs)

# Move tick marks
  #  Get tick mark length
  plot_theme <- function(p) {
    plyr::defaults(p$theme, theme_get())
  }
  tml <- plot_theme(m)$axis.ticks.length   # Tick mark length

ticks$grobs[[2]]$y <- ticks$grobs[[2]]$y - unit(1, "npc") + tml

# Swap tick mark labels' margins and justifications
ticks$grobs[[1]] <- vinvert_title_grob(ticks$grobs[[1]])

# Put ticks and tick mark labels back into xaxis
xaxis$children[[2]] <- ticks

# Add axis to top of g1
g1 <- gtable_add_rows(g1, g1$heights[g1$layout[index, ]$t], pp$t)
g1 <- gtable_add_grob(g1, xaxis, pp$t+1, pp$l, pp$t+1, pp$r, clip = "off", name = "axis-t")

# Remove original x axis and xlab
g1 = g1[-c(9,10), ]

# Draw it
grid.newpage()
grid.draw(g1)

Log10 x 轴在顶部，y 轴 geom_line

Log10 x-axis on top and y-axis geom_line

r

ggplot2