How to change fill color in each facet using ggplot2

Question

I am trying to visualize data using ggplot2.

I have 3 facet figures with geombars in each

So, here each facet represents a particular variable that I have used in other graphs where ggplot2 assigns them to fill colors by default.

The faceted plots are black by default.

 I can change the fill color for all three panels but haven't found how to change each panel's fill to a different color.

Here is a sample data and code to represent the basic idea:

df = data.frame(matrix(data=c(1,3,1,2,3,1,2,3,2,3,1,2,3,1,2,3,
                              1,3,2,1,2,2,2,3,3,3,1,1,1,3,3,2), 
                       ncol=2,byrow=TRUE))
dimnames(df)[[2]] =c("x","y")

dodgebars <- 
  ggplot(data = df,aes(factor(y),fill=factor(x))) +
  geom_bar(aes(group=factor(x)),
           position="dodge")
facetedbars <- 
  ggplot(data = df, aes(factor(y))) +
  geom_bar(aes(group=x)) +
  facet_grid(~x)

How to match the color of each facet to fill its cover in "dodgebars"?

Answer 1

You can map the facetting variable to fill color.

 Then, every facet gets a different bar color:

facetedbars + aes(fill = as.factor(x))