How can I move x-axis labels away from the centre of a ggplot that uses coord

I'm making a polar-transformed barplot in which several of the x-axis labels overlap with the plot area. For context, I'm working on a shiny application that you can find a copy of

CodePudding user response：

This doesn't look nearly as nice as the answer from @Allan Cameron using his very slick {geomtextpath} library but has the (possible) advantage of being easy to implement with native {ggplot2}. Here we simply use expand_limits() in the y direction to push the axis further from the plot and leave room for the label. It's a bit of a hack because I came up with a fudge factor for how far to expand based on the length of the label and the size of that bar. It works OK with labels of a certain size but if they get really long it will break down a bit unless you introduce a line break. Also you can add theme(plot.margin = unit(c(3, 0, 3, 0), "lines")) to get more space around the plot to avoid cutting of super long labels.

library(tidyverse)

# data
plotThis <- 
  tibble(
  names = c("foo", "bar", "baz", "biff", "zoop", "sesquipedalian"),
  values = c(100, 150, 42, 135.45, 177, 182))

# calculate scaling of axis based on longest label
new_max_y <- 
  plotThis %>% 
  mutate(nchar = nchar(names),
         new_max_y = values * (1   0.01 * nchar)) %>% 
  pull(new_max_y) %>% 
  max()

# plot - expand margins if names get really long
plotThis %>% 
  ggplot(aes(x = names, y = values))  
  geom_col(color = "black", fill = "blue", width = 1)  
  coord_polar(clip = "off")  
  theme_minimal()  
  scale_y_continuous(name = NULL, breaks = NULL)  
  expand_limits(y = c(0, new_max_y))  
  xlab(NULL)

^{Created on 2022-02-15 by the reprex package (v2.0.1)}