箱形图的传奇定制

Question

我有这个箱线图，然后我试图在它上面绘制两个不同颜色的不同点，以便用户可以看到它们落在箱线图上的位置，并将它们相互比较。问题是，我希望图例显示两个带有相应颜色的点及其ID。相反，图例显示了boxplot类别/颜色。如何覆盖图例以仅显示我想要的内容？这是我的代码：

library(datasets)
library(ggplot2)

data(airquality)
airquality$Month <- factor(airquality$Month,
                       labels = c("May", "Jun", "Jul", "Aug", "Sep"))
airquality$ID <-seq(1:nrow(airquality))
dataPoint <- airquality[11,]
dataPoint2 <- airquality[17,]
plt <- ggplot(airquality, aes(x = Month, y = Ozone, color = Month)) +
  geom_boxplot(show.legend=TRUE,outlier.shape = NA) +
  geom_point(data = dataPoint, color='darkblue', aes(x = Month, y =    Ozone), size = 3,show.legend=TRUE) +
  geom_point(data = dataPoint2, color='darkred', aes(x = Month, y = Ozone), size = 3,show.legend=TRUE) +
  theme(legend.position = "bottom")
plt

Answer 1

我会通过将点映射到不同的美学来实现这一点。如果show.legend在这种情况下设置为FALSE，那么图例将单独显示。您还可以映射到点形状或任何其他美学。或者，您可以映射boxplot geom的fill，并映射点geom的color。

例如：

library(datasets)
library(ggplot2)

data(airquality)
airquality$Month <- factor(airquality$Month,
                       labels = c("May", "Jun", "Jul", "Aug", "Sep"))
airquality$ID <-seq(1:nrow(airquality))
points <- c(11, 17)
airquality$Points <- NA
airquality$Points[points] <- c("Point a", "Point b")
plt <- ggplot(airquality, aes(x = Month, y = Ozone, color = Month)) +
  geom_boxplot(outlier.shape = NA) +
  geom_point(data = airquality[!is.na(airquality$Points), ], 
  mapping=aes(x = Month, y = Ozone, fill = Points), size = 3, shape = 21, inherit.aes=FALSE) +
  theme(legend.position = "bottom")
plt

Answer 2

最简单的绘制图形的方法是：

• 合并dataPoint个数据集（使用rbind）。像这样你只需要拨打一个geom_point
• 对于boxplot，请使用fill而不是color
• 使用scale_color_manual
定义点颜色

代码：

# Combine datasets
dataPoints <- rbind(dataPoint, dataPoint2)

# Plot
ggplot(airquality, aes(Month, Ozone, fill = Month)) +
    geom_boxplot(outlier.shape = NA) +
    geom_point(data = dataPoints, 
               aes(Month, Ozone, color = factor(ID)), 
               size = 3) +
    labs(color = "ID",
         fill = "Month") +
    scale_color_manual(values = c("darkblue", "darkred")) +
    theme(legend.position = "bottom")

结果：

PS：我不会为月份（填充）添加调色板，因为此信息已经显示在x轴上（冗余信息）。要删除填充图例，您可以添加guides(fill = FALSE)。

在OP评论后编辑以使用形状：

如果你想要形状而不是颜色

ggplot(airquality, aes(Month, Ozone, fill = Month)) +
    geom_boxplot(outlier.shape = NA) +
    geom_point(data = dataPoints, 
               aes(Month, Ozone, shape = factor(ID)), 
               size = 3) +
    labs(shape = "ID",
         fill = "Month") +
    scale_shape_manual(values = c(15, 17)) +
    theme(legend.position = "bottom")