How do I limit the range of the viridis colour scale?
I have two sets of data, which I want to present using a heat map with the viridis color scale. For the first data set, my values range from 0 to 1.2 and I can easily see the differences I want to see. However my second data set has some outliers, resulting in a range from 0 to 2. Now it's harder to see the differences in the interesting range between 0 and 1 and it's more diffucult to compare the two images directly. Is there a possibility to show the data from 0 to 1.2 using the viridis colour scale while showing the higher values in yellow ("highest" colour of the viridis scale)? Here is an example:
library(viridis)
#Create Data
DataSet1 <- expand.grid(x = 0:5, y = 0:5)
DataSet1$z <- runif(36, 0, 1.2)
DataSet2 <- expand.grid(x = 0:5, y = 0:5)
DataSet2$z <- runif(36, 0, 2)
#Plot Data
ggplot(DataSet1, aes(x, y, fill = z)) +
geom_tile() +
scale_fill_viridis() +
geom_text(aes(label = round(z, 2)), size = 2)
DataSet1: Differences between 0.5 and 0.7 are easy to see
ggplot(DataSet2, aes(x, y, fill = z)) +
geom_tile() +
scale_fill_viridis() +
geom_text(aes(label = round(z, 2)), size = 2)
DataSet2: Differences between 0.5 and 0.7 are diffucult to see
Answer
@ClausWilke's solution is better because it shows in the legend, but sometimes one just needs a quick solution without having to write too much specific code. This one also relies on the scales package
ggplot(DataSet2, aes(x, y, fill = z)) +
geom_tile() +
scale_fill_viridis(limits = c(0.2, 1), oob = scales::squish) +
geom_text(aes(label = round(z, 2)), size = 2)
