Heatmap: order y axis based on single x axis variable

user_18410587 0
Viewed 25

In my heatmap I would like to order Species based on percent value (decreasing) in Haul 1. Here is my current code:

ggplot(data, aes(Haul, Species)) + geom_tile(aes(fill = Percent)) + 
  scale_fill_gradient(low = "white", high = "red") + 
  labs(fill = "% Sites")+ theme_bw()

enter image description here

So the Species order should be b, c, d, a, based on decreasing Percent in Haul 1. I have tried using reorder() but can't find a way to specify the ordering based on Haul 1.

ggplot(data, aes(Haul, reorder(Species, Percent))) + geom_tile(aes(fill = Percent)) + 
  scale_fill_gradient(low = "white", high = "red") + 
  labs(fill = "% Sites")+ theme_bw()

My dataframe is set up like this:

Species = rep(c("a","b","c","d"),3)
Haul = rep(c(1,2,3),4)
Percent = c(25,0,25,50,25,0,75,0,50,100,0,50)
data = data.frame(Species, Haul, Percent)

Thank you for your help!

Elise

heatmap ggplot2 r
1 Answers

In the reorder, we can use ifelse to make other haul values NA:

ggplot(data, aes(Haul, reorder(Species, ifelse(Haul == 1, Percent, NA), na.rm = TRUE))) + 
  geom_tile(aes(fill = Percent)) + 
  scale_fill_gradient(low = "white", high = "red") + 
  labs(fill = "% Sites", y = "Species") +
  theme_bw()

enter image description here

user_9030610
Related