CODEWITHSUNDEEP
rggplot2
asuka
asuka

Reputation: 2439

ggplot2 - Keep the colours with empty classes

Is there any automatic way of keeping the different colours that ggplot2 uses it doesn't matter if the a specific class is present or not in a given plot?

For the following problem:

library(ggplot2)

set.seed(100)

data <- data.frame(y=rnorm(100,2),class=sample(c("A","B","C"),100,rep=T),
                   stringsAsFactors=T)

output <- ggplot(data[which(data[,"class"] != "B"),], 
                 aes_string(x="class", y="y", fill="class")) +
  geom_boxplot() +
  scale_x_discrete(limits=c("A","B","C"), "class", drop=F)

If I don't use the samples of class B, I get the following plot: Boxplot without Class B

output <- ggplot(data,
                 aes_string(x="class", y="y", fill="class")) +
  geom_boxplot() +
  scale_x_discrete(limits=c("A","B","C"), "class", drop=F)

But I would like to keep the palette in the same way it looks if all the classes are present: Boxplot with all the Classes

I know that I can put the palette manually, but I would like to know it I can force ggplot to take into account all the classes even though one of them is not present.

Upvotes: 0

Views: 392

Answers (1)

Roland
Roland

Reputation: 132969

You already know how to do this:

ggplot(data[which(data[,"class"] != "B"),], 
                 aes_string(x="class", y="y", fill="class")) +
  geom_boxplot() +
  scale_x_discrete(limits=c("A","B","C"), "class", drop=F) +
  scale_fill_discrete(drop = F)

resulting plot

Upvotes: 1

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