ggplot2: Add text next to point only if conditions are met

Question

is there a way to add text next to a point only if a value is met? For example I have here,

library(ggplot2)
library(ggrepel)

x = c(0.8846, 1.1554, 0.9317, 0.9703, 0.9053, 0.9454, 1.0146, 0.9012, 
      0.9055, 1.3307)
y = c(0.9828, 1.0329, 0.931, 1.3794, 0.9273, 0.9605, 1.0259, 0.9542, 
      0.9717, 0.9357)
z= c("a", "b", "c", "d", "e", "f", 
             "g", "h", "i", "j")


df <- data.frame(x = x, y = y, z = z)
ggplot(data = df, aes(x = x, y = y)) + theme_bw() + 
geom_text_repel(aes(label = z), 
box.padding = unit(0.45, "lines")) +
geom_point(colour = "green", size = 3)

This will give me something that looks like this.

however what if I only want the text to appear if y > 1.3 in this case only "d" will be labeled. Any ideas? thanks in advance.

Answer 1

If you specify the data within the geom_text_repel call:

ggplot(data = df, aes(x = x, y = y)) + theme_bw() + 
    geom_text_repel(data = df[which(df$y > 1.3),], 
                    aes(label = z), 
                    box.padding = unit(0.45, "lines")) +
    geom_point(colour = "green", size = 3)

Answer 2

Subset the data within the geom_text_repel parameter.

e.g.

library(ggplot2)
library(ggrepel)

x = c(0.8846, 1.1554, 0.9317, 0.9703, 0.9053, 0.9454, 1.0146, 0.9012, 
      0.9055, 1.3307)
y = c(0.9828, 1.0329, 0.931, 1.3794, 0.9273, 0.9605, 1.0259, 0.9542, 
      0.9717, 0.9357)
z= c("a", "b", "c", "d", "e", "f", 
     "g", "h", "i", "j")


df = data.frame(x = x, y = y, z = z)
ggplot(data = df, aes(x = x, y = y)) + theme_bw() + 
  # Subset the data as it relates to the y value
  geom_text_repel(data = subset(df, y > 1.3), aes(label = z), 
                  box.padding = unit(0.45, "lines")) +
  geom_point(colour = "green", size = 3)