The parameter alpha in the R package ggplot2 is used to express the transparency of the fill colour of the function geom_
However for the function geom_rect it might not work as aspected.
In my latest work, I tried to combine different geom function but I was stuck when all was covered when I used geom_rect.
Let’s see an example:
library("dplyr")
library("ggplot2")
df =
data.frame(
x = c(rep(1, 25), rep(2, 25), rep(3, 25)),
y = c(sample(1:50, 25), sample(51:100, 25), sample(101:150, 25)),
classes = c(rep("A", 25), rep("B", 25), rep("C", 25)))
head(df)
# x y classes
#1 1 45 A
#2 1 4 A
#3 1 41 A
#4 1 32 A
#5 1 8 A
36 1 14 A
If we plot the data using geom_jitter and geom_boxplot we obtain the plot:
ggplot(data = df,
aes(x = x, y = y, colour = classes)) +
geom_jitter() +
geom_boxplot(alpha = 0.2) +
theme_minimal()
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