Wants to create a boxplot with error bar, but there is issue to display the whisker properly, following is what I did:
# Prepare data
library(ggplot2)
data(airquality)
airquality$Month <- factor(airquality$Month,
labels = c("May", "Jun", "Jul", "Aug", "Sep"))
# Generate new category variable
airquality_trimmed <- airquality[which(airquality$Month == "Jul" |
airquality$Month == "Aug" |
airquality$Month == "Sep"), ]
airquality_trimmed$Temp.f <- factor(ifelse(airquality_trimmed$Temp > mean(airquality_trimmed$Temp), 1, 0),
labels = c("Low temp", "High temp"))
# Create boxplot without whsker, it works well
ggplot(airquality_trimmed, aes(x = Month, y = Ozone, fill = Temp.f)) +
geom_boxplot(alpha=0.7)
# However, the chart messed up if adding error bar, how to fit this problem? Thank you!
ggplot(airquality_trimmed, aes(x = Month, y = Ozone, fill = Temp.f)) +
geom_boxplot(alpha=0.7) + stat_boxplot(geom="errorbar", width=0.2)