Plot coloured boxes around axis label

Question

Consider this simple example

library(tidyverse)
tibble(x = as.factor(c('good', 'neutral', 'bad')),
       y = as.factor(c('bad', 'neutral', 'bad'))) %>% 
  ggplot(aes(x = x, y = y)) + geom_point()

I would like to put the x labels (good, neutral, bad) in different colored boxes. For instance, good (on both the x and y axis) would be surrounded on a small green box, and so on.

Can I do that in ggplot2?

Answer 1

Like this?

tibble(x = as.factor(c('good', 'neutral', 'bad')),
y = as.factor(c('bad', 'neutral', 'bad'))) %>%
ggplot(aes(x = x, y = y)) + 
  geom_point() + 
  theme(axis.text.x = element_text(color = c('red', 'blue', 'green')))

Your Plot:

EDIT

An alternate pretty Ghetto solution using grid

tibble(x = as.factor(c('good', 'neutral', 'bad')),
y = as.factor(c('bad', 'neutral', 'bad'))) %>%
ggplot(aes(x = x, y = y)) + 
  geom_point()

grid::grid.polygon(x = c(.3,.3,.25,.25), y = c(.07,.04,.04,.07),gp = gpar(col = 'green', fill = 'green', alpha = .5))
grid::grid.polygon(x = c(.525,.525,.575,.575), y = c(.07,.04,.04,.07),gp = gpar(col = 'red', fill = 'red', alpha = .5))
grid::grid.polygon(x = c(.79,.79,.86,.86), y = c(.07,.04,.04,.07),gp = gpar(col = 'blue', fill = 'blue', alpha = .5))

Answer 2

One approach could be this:

tibble(x = as.factor(c('good', 'neutral', 'bad')),
       y = as.factor(c('bad', 'neutral', 'bad'))) %>% 
  ggplot(aes(x = x, y = y)) + geom_point()+
  geom_rect(aes(xmin=0.5, xmax=1.5, ymin=-Inf, ymax=Inf), fill="red", alpha=0.1)+
  geom_rect(aes(xmin=1.5, xmax=2.5, ymin=-Inf, ymax=Inf), fill="yellow", alpha=0.1)+
  geom_rect(aes(xmin=2.5, xmax=3.5, ymin=-Inf, ymax=Inf), fill="green", alpha=0.1)

With geom_rect() you can add colored backgrounds:

Answer 3

Another approach

Create a vector of colors and pass them into axis.text.x() option of theme().

# data
x = as.factor(c('good', 'neutral', 'bad'))
y = as.factor(c('bad', 'neutral', 'bad'))
df<- data.frame(x,y)

# create a vector of colors
mycolors<- c("red","blue","green")
library(ggplot2)
ggplot(df, aes(x = x, y=y))+
  geom_point()+
  theme(axis.text.x = element_text(colour = mycolors))

Answer 4

Solution using geom_label outside the plot area:

ggplot(data, aes(x, y)) +
  geom_point() +
  geom_label(aes(0.3, y, label = y, fill = y), hjust = 0) +
  geom_label(aes(x, 0.45, label = x, fill = x)) +
  theme_minimal() +
  theme(
    axis.text = element_blank(),
    axis.ticks = element_blank(),
    legend.position = "none"
  ) +
  coord_cartesian(xlim = c(1, 3), ylim = c(1, 2), clip = "off")

---

Another solution

You should create geom_rect with borders, but without fill and plot them outside the plot area (using coord_cartesian):

library(tidyverse)
data <- tibble(
  x = as.factor(c('good', 'neutral', 'bad')),
  y = as.factor(c('bad', 'neutral', 'bad'))
)
ggplot(data, aes(x, y)) +
  geom_point() +
  # put rects on y-axis
  geom_rect(aes(xmin = 0.1, xmax = 0.45, color = y,
                ymin = as.numeric(y) - 0.1, ymax = as.numeric(y) + 0.1),
            fill = NA, size = 3) +
  # put rects on x-axis
  geom_rect(aes(ymin = 0.3, ymax = 0.4, color = x,
                xmin = as.numeric(x) - 0.15, xmax = as.numeric(x) + 0.15),
            fill = NA, size = 3) +
  # Here it's important to specify that your axis goes from 1 to max number of levels
  coord_cartesian(xlim = c(1, 3), ylim = c(1, 2), clip = "off")