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rggplot2facet

Adding a X axis title to faceted ggballoonplot

I followed the code on this page to create balloon plots with ggballoonplot() using facet.by. I wanted to add an x axis title, so I followed what was recommended in the question asked here to which described how to add an axis label to a balloon plot.

library(ggplot2)
df <- as.data.frame(HairEyeColor)
p<-ggballoonplot(df, x = "Hair", y = "Eye", size = "Freq",
              fill = "Freq", facet.by = "Sex",
              ggtheme = theme_bw()) +
              scale_fill_viridis_c(option = "C")+
              xlab("Group")

Which produces this plot, missing the xlab that I thought I had specified.

Balloon plot

I also tried to assign an xlab as follows, but it also didn't work as planned (produces the same plot as shown above).

p2<-ggballoonplot(df, x = "Hair", y = "Eye", size = "Freq",
                  fill = "Freq", facet.by = "Sex",
                  ggtheme = theme_bw()) +
  scale_fill_viridis_c(option = "C")+
  labs(x = "Group")

Any ideas? As per the SO post I linked to, someone suggested it might be a print/rendering settings issue, but they didn't offer any suggestions on how to pursue that possibility and resolve the issue. Thanks!

Solution

  • The issue is that under the hood ggballoonplot removes the axis title via theme(), i.e. axis.title.x = element_blank(). Hence, adding a title via xlab() or labs() has no effect. Instead you have to override the theme() element, too, using axis.title.x = element_text():

    library(ggplot2)
library(ggpubr)

df <- as.data.frame(HairEyeColor)
ggballoonplot(df,
  x = "Hair", y = "Eye", size = "Freq",
  fill = "Freq", facet.by = "Sex",
  ggtheme = theme_bw()
) +
  scale_fill_viridis_c(option = "C") +
  xlab("Group") +
  theme(axis.title.x = element_text())