How to increase the font size of label names

Question

I want to increase the font size of label names. I tried with geom_label_repel(aes(label = names, label.size = 5), box.padding = unit(0.5, "lines")) . But the size doesn't affect the labels.

ggplot(df, aes(x,y,label=names)) +
  geom_point(colour = "red", size = 3) +
  geom_smooth(method=lm, se=FALSE, colour = "blue") +
  geom_label_repel(aes(label = names, label.size = 5),
                   box.padding = unit(0.5, "lines")) +
  xlim(0,2.5) +
  ylim(0,2.5) +
  theme( plot.title=element_text(size=16,face="bold"),
         axis.text=element_text(size=18),
         axis.title=element_text(size=20,face="bold"))

Answer 1

As I just wrote in the comment, it is not clear from your code, whether you want the label size fixed (the same for all labels) or dependent on a column of df. Guess you want it fixed. In that case, setting the size is not done within aes(...). Also, it is not necessary to repeat label=names. After reading https://cran.r-project.org/web/packages/ggrepel/vignettes/ggrepel.html we can thus write:

ggplot(df, aes(x,y,label=names)) +
  geom_point(colour = "red", size = 3) +
  geom_smooth(method=lm, se=FALSE, colour = "blue") +
  geom_label_repel(size = 5,
                   box.padding = unit(0.5, "lines")) +
  xlim(0,2.5) +
  ylim(0,2.5) +
  theme( plot.title=element_text(size=16,face="bold"),
         axis.text=element_text(size=18),
         axis.title=element_text(size=20,face="bold"))