R ggrepel：隐藏一些标签

Question

Hi I been getting Aesthetics error when trying to only display labels for certain subsets. For example.

library("ggplot2")
library(gplots)
library(ggrepel)

set.seed(10)
data <- data.frame(label=letters[1:21], number= runif(21, min=0, max=100))
data$label <-factor(data$label)

ggplot(data, aes(x=label, y=number, fill=data$label )) +
geom_bar(stat="identity") +
geom_text_repel(data=  data[data$number > 80,], aes(label =data$label ), 
                  arrow = arrow(length = unit(0.01, 'npc')), box.padding = unit(1.5, 'lines'),color="black"   )

When I do this I get the following error

Error: Aesthetics must be either length 1 or the same as the data (2): label, x, y, fill

even if I replace the label with a vector such as c("label1","label2") I still get an error.

I'm doing something wrong but I can't figure it out. The only way I can do this is to create a separate vector with the same length and use that as the label, however I think there is a way to subset directly. thanks!

Answer 1

Change the code to:

ggplot(data, aes(x=label, y=number, fill=data$label )) +
geom_bar(stat="identity") +
geom_text_repel(data=  data[data$number > 80,], aes(label =label ), ##<- Change here
                  arrow = arrow(length = unit(0.01, 'npc')), box.padding = unit(1.5, 'lines'),color="black"   )

The problem is that in the call to aes within geom_text_repel() you use data$label , a column within the 21 row dataframe, whereas you want label to be evaluated within the 2 row subset of the data.

In this case, you've obscured the problem by calling your data data , it might be more straightforward to spot the error if you'd called it something more meaningful.