问题
EDIT: Added the boxplot generated with standard boxplot() function.
Given the iris dataste, the following code:
boxplot(iris[,])
Creates a boxplot with five boxes, one for each variable, without splitting them into categories such as, for instance, species. While this is simple enough, I have been unable to do the same in ggplot2.
My question, then, is simple: how can I achieve this?
回答1:
Species is a factor with three levels (setosa, versicolor and virginica). I think it doesn't make sense if you plot it with the other variables.
It makes more sense if you want to plot all other 4 variables (Sepal.Length, Sepal.Width, Petal.Length, and Petal.Width) in one plot as below
library(dplyr)
library(tidyr)
library(ggplot2)
iris %>% dplyr::select(Species, everything()) %>% tidyr::gather("id", "value",2:5) %>%
ggplot(., aes(x = id, y = value))+geom_boxplot()
If you want to plot all 5 variables in the same plot, you need to convert species to be numeric
iris %>% dplyr::mutate(Species = as.numeric(Species)) %>% tidyr::gather("id", "value",1:5) %>%
ggplot(., aes(x = id, y = value))+geom_boxplot()
来源：https://stackoverflow.com/questions/42990342/generate-boxplots-for-multiple-variables-in-ggplot2-without-factoring