Color the group in ggplot violin plot

Question

I am new to R programming. Stuck while plotting ggplot violin plot. I wish to give color blue, green and red color to my 3 groups. Here is my dataframe:

> print(employee_withoutEmployeeID[1:5,])
> 
  EnvironmentSatisfaction JobSatisfaction WorkLifeBalance
1                       3               4               2
2                       3               2               4
3                       2               2               1
4                       4               4               3
5                       4               1               3

What I am trying is:

png(file="answer5.png")
answer5 <- ggplot(stack(employee_withoutEmployeeID), aes(x = ind, y= values) )
answer5 + geom_violin()  + scale_fill_manual(values=c("#0000FF", "#00FF00", "#FF0000")) + 
  labs(title="Answer 5", 
       subtitle="",
       caption="Answer 5",
       x="Measure",
       y="Rating")  
dev.off()

I am getting my violin plot plotted correctly, but there is no color fill. I am not sure, how and where to use scale_fill_manual Please suggest

Answer 1

The fill aestetic needs to be specified in geom_violin :

library(ggplot2)
ggplot(iris, aes(x= Species, y = Sepal.Width) ) +
       geom_violin(aes(fill= Species))  + 
       scale_color_manual(values=c("#0000FF", "#00FF00", "#FF0000")) + 
       labs(title="Answer 5", subtitle="",  caption="Answer 5",
         x="Measure", y="Rating")  

Answer 2

You need to define the variable to fill on. The stack function will add the ind column onto your input data.frame, thus I added the fill=ind into the aes option.

answer5 <- ggplot(stack(employee_withoutEmployeeID), aes(x = ind, y= values, fill=ind) )
answer5 + geom_violin()  + scale_fill_manual(values=c("#0000FF", "#00FF00", "#FF0000")) + 
   labs(title="Answer 5", 
        subtitle="",
        caption="Answer 5",
        x="Measure",
        y="Rating")