即使所有组都为空，也显示空组

Question

使用scale_x_discrete(drop = FALSE)I 设法将空组保持在 x 轴上的位置：

library(ggplot2)
iris_filtered <- subset(iris, Sepal.Length > 7)
ggplot(data = iris_filtered, mapping = aes(x = Species, y = Sepal.Width)) +
  geom_boxplot() +
  scale_x_discrete(drop = FALSE)

除非所有组都为空，否则我得到：

iris_filtered <- subset(iris, Sepal.Length > 8)
ggplot(data = iris_filtered, mapping = aes(x = Species, y = Sepal.Width)) +
  geom_boxplot() +
  scale_x_discrete(drop = FALSE)

我希望的输出是：

Answer 1

您可以只指定 x 轴限制：

iris_filtered <- subset(iris, Sepal.Length > 8)
ggplot(data = iris_filtered, mapping = aes(x = Species, y = Sepal.Width)) +
  geom_boxplot() +
  scale_x_discrete(drop = FALSE, limits = unique((iris$Species))

显示 y 轴比例的类似方法：

ggplot(data = iris_filtered, mapping = aes(x = Species, y = Sepal.Width)) +
  geom_boxplot() +
  scale_x_discrete(drop = FALSE, limits = c("a","b","c")) +
  ylim(min(iris$Sepal.Length), max(iris$Sepal.Length))