ggplot："size-robust" 将水平图例放置在右下角的方法
ggplot: "size-robust" way to place horizontal legend at the bottom-right
我正在尝试在绘图区域外的右下角放置一个水平图例。
我知道之前已经讨论过了。然而，经过一个漫长的令人沮丧的早晨，我无法找到一个“尺寸稳健”的解决方案。
以下是我找到的 3 个解决方案：
- 当我将
legend.position 设置为 bottom 时：图例位于
底部中心，但我无法使用将它推到右侧
legend.justification
- 当我将
legend.position 设置为 c(1,0) 时：图例位于
右下角。但是，图例位于情节内。
- 当我添加
plot.margin 并将 legend.position 向下推时：
图例位于绘图的右下角和外部。但是，当我更改绘图区域的大小时，图例不再正确定位。
方案三定位不正确：
可重现代码：
# Generate random data------
sample.n = 50
sample.data = data.frame(x = runif(sample.n,0,1), y = runif(sample.n,0,1), value = runif(sample.n,0,10))
# Plot ------
library(ggplot2)
# Margins are fine. And If I change the size of the plotting area, the legend will always be bottom- centered
# Problem: Can't push it to the right side
ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal", legend.position = "bottom")
# Pushed to the bottom-right Successfully
# Problem: Legend inside the plot
ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal",legend.position = c(1,0)) # Problem: inside plot
# Placed at the bottom-right corner outside the plot region
# Problem: If I change the size of the plotting region, the legend will not be cornred
ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal", legend.position = c(0.9,-0.2),
plot.margin = unit(c(1, 1, 5, 1), "lines"))
Theme-Legend 的文档：
legend.position the position of legends ("none", "left", "right",
"bottom", "top", or two-element numeric vector)
legend.justification anchor point for positioning legend inside plot
("center" or two-element numeric vector)
Edit 使用 2.2.0，可以在主题中使用 legend.justification 和 legend.margin 将图例推到右边。
# Generate random data------
sample.n = 50
sample.data = data.frame(x = runif(sample.n,0,1), y = runif(sample.n,0,1), value = runif(sample.n,0,10))
# Plot ------
library(ggplot2)
library(gtable)
library(grid)
p = ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal", legend.position = "bottom",
legend.box.background = element_rect(colour = "black"))
p + theme(legend.justification = "right",
legend.margin = margin(t = 2, r = 0, b = 2, l = 2, unit = "mm"))
对于它的价值，我保留了原来的答案，但更新到了 ggplot 版本 2.2.0。
我在这里所做的是从绘图中提取图例，将图例包裹在视口中，使视口位于右侧，将图例放回绘图中，并删除原始图例。
# Generate random data------
sample.n = 50
sample.data = data.frame(x = runif(sample.n,0,1), y = runif(sample.n,0,1), value = runif(sample.n,0,10))
# Plot ------
library(ggplot2)
library(gtable)
library(grid)
p = ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal", legend.position = "bottom")
# Get the ggplot grob
g = ggplotGrob(p)
# Get the legend
index = which(g$layout$name == "guide-box")
leg = g$grobs[[index]]
# Wrap the legend in a viewport
leg$vp = viewport(x = unit(1, "npc"), width = sum(leg$widths), just = "right")
### Put the legend back into the plot
# First, get the current location of the legend
pos = g$layout[index, ]
g = gtable_add_grob(g, leg, t = pos$t, l = pos$l)
# Remove the original legend
g$grobs <- g$grobs[-index]
g$layout <- g$layout[-index, ]
# Draw the chart
grid.newpage()
grid.draw(g)
请注意，图例已向右移动，但图例的右边缘与绘图面板的右边缘并不完全对齐。这是因为图例具有内部边距。图例本身有边距，但该边距设置为 0 毫米。要使图例与绘图面板对齐，需要进行更多操作。在下文中，内部边距（和图例边距）设置为 0。此外，图例和图例的内部部分包裹在右对齐视口中。
# Get the ggplot grob
g = ggplotGrob(p)
# Get the legend
index = which(g$layout$name == "guide-box")
leg = g$grobs[[index]]
# Remove the legend right margin and an internal margin
leg$widths[4] = unit(0, "mm")
leg$grobs[[1]]$widths[5] = unit(0, "mm")
# Wrap the legend in a viewport
leg$vp = viewport(x = unit(1, "npc"), width = sum(leg$widths), just = "right")
# Wrap the internal part of the legend in a right justified viewport
leg$grobs[[1]]$vp = viewport(x = unit(1, "npc"), width = sum(leg$grobs[[1]]$widths), just = "right")
### Put the legend back into the plot
# First, get the current location of the legend
pos = g$layout[index, ]
g = gtable_add_grob(g, leg, t = pos$t, l = pos$l)
# Remove the original legend
g$grobs <- g$grobs[-index]
g$layout <- g$layout[-index, ]
# Draw the chart
grid.newpage()
grid.draw(g)
我正在尝试在绘图区域外的右下角放置一个水平图例。
我知道之前已经讨论过了。然而，经过一个漫长的令人沮丧的早晨，我无法找到一个“尺寸稳健”的解决方案。
以下是我找到的 3 个解决方案：
- 当我将
legend.position设置为bottom时：图例位于 底部中心，但我无法使用将它推到右侧legend.justification - 当我将
legend.position设置为c(1,0)时：图例位于 右下角。但是，图例位于情节内。 - 当我添加
plot.margin并将legend.position向下推时： 图例位于绘图的右下角和外部。但是，当我更改绘图区域的大小时，图例不再正确定位。
方案三定位不正确：
可重现代码：
# Generate random data------
sample.n = 50
sample.data = data.frame(x = runif(sample.n,0,1), y = runif(sample.n,0,1), value = runif(sample.n,0,10))
# Plot ------
library(ggplot2)
# Margins are fine. And If I change the size of the plotting area, the legend will always be bottom- centered
# Problem: Can't push it to the right side
ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal", legend.position = "bottom")
# Pushed to the bottom-right Successfully
# Problem: Legend inside the plot
ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal",legend.position = c(1,0)) # Problem: inside plot
# Placed at the bottom-right corner outside the plot region
# Problem: If I change the size of the plotting region, the legend will not be cornred
ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal", legend.position = c(0.9,-0.2),
plot.margin = unit(c(1, 1, 5, 1), "lines"))
Theme-Legend 的文档：
legend.position the position of legends ("none", "left", "right", "bottom", "top", or two-element numeric vector)
legend.justification anchor point for positioning legend inside plot ("center" or two-element numeric vector)
Edit 使用 2.2.0，可以在主题中使用 legend.justification 和 legend.margin 将图例推到右边。
# Generate random data------
sample.n = 50
sample.data = data.frame(x = runif(sample.n,0,1), y = runif(sample.n,0,1), value = runif(sample.n,0,10))
# Plot ------
library(ggplot2)
library(gtable)
library(grid)
p = ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal", legend.position = "bottom",
legend.box.background = element_rect(colour = "black"))
p + theme(legend.justification = "right",
legend.margin = margin(t = 2, r = 0, b = 2, l = 2, unit = "mm"))
对于它的价值，我保留了原来的答案，但更新到了 ggplot 版本 2.2.0。
我在这里所做的是从绘图中提取图例，将图例包裹在视口中，使视口位于右侧，将图例放回绘图中，并删除原始图例。
# Generate random data------
sample.n = 50
sample.data = data.frame(x = runif(sample.n,0,1), y = runif(sample.n,0,1), value = runif(sample.n,0,10))
# Plot ------
library(ggplot2)
library(gtable)
library(grid)
p = ggplot(sample.data, aes(x = x, y = y, color = value)) + geom_point() +
theme(legend.direction = "horizontal", legend.position = "bottom")
# Get the ggplot grob
g = ggplotGrob(p)
# Get the legend
index = which(g$layout$name == "guide-box")
leg = g$grobs[[index]]
# Wrap the legend in a viewport
leg$vp = viewport(x = unit(1, "npc"), width = sum(leg$widths), just = "right")
### Put the legend back into the plot
# First, get the current location of the legend
pos = g$layout[index, ]
g = gtable_add_grob(g, leg, t = pos$t, l = pos$l)
# Remove the original legend
g$grobs <- g$grobs[-index]
g$layout <- g$layout[-index, ]
# Draw the chart
grid.newpage()
grid.draw(g)
请注意，图例已向右移动，但图例的右边缘与绘图面板的右边缘并不完全对齐。这是因为图例具有内部边距。图例本身有边距，但该边距设置为 0 毫米。要使图例与绘图面板对齐，需要进行更多操作。在下文中，内部边距（和图例边距）设置为 0。此外，图例和图例的内部部分包裹在右对齐视口中。
# Get the ggplot grob
g = ggplotGrob(p)
# Get the legend
index = which(g$layout$name == "guide-box")
leg = g$grobs[[index]]
# Remove the legend right margin and an internal margin
leg$widths[4] = unit(0, "mm")
leg$grobs[[1]]$widths[5] = unit(0, "mm")
# Wrap the legend in a viewport
leg$vp = viewport(x = unit(1, "npc"), width = sum(leg$widths), just = "right")
# Wrap the internal part of the legend in a right justified viewport
leg$grobs[[1]]$vp = viewport(x = unit(1, "npc"), width = sum(leg$grobs[[1]]$widths), just = "right")
### Put the legend back into the plot
# First, get the current location of the legend
pos = g$layout[index, ]
g = gtable_add_grob(g, leg, t = pos$t, l = pos$l)
# Remove the original legend
g$grobs <- g$grobs[-index]
g$layout <- g$layout[-index, ]
# Draw the chart
grid.newpage()
grid.draw(g)