Replace x axis labels with colored bars to get a gradient effect in R-CodePudding

I'm building a barplot with RNA reads % in ggplot, I did this:

ggplot(tipos_exo,aes(x = reorder(sample, -value),y = value,fill = variable))  
     geom_bar( stat = "identity")

barplot

I need to replace the x axis labels with colored bars, each sample belongs to a specific batch and I looking for this effect:

Colored bars

Any thoughts?

CodePudding user response：

One option to achieve your desired result would be to create your axis colorbar as a second plot and glue it to the main plot via the patchwork package.

For the colorbar I use geom_tile and remove all non-data ink using theme_void. As a first step I reorder your sample column by value and get rid of the duplicated sample categories using dplyr::distinct.

Using some fake random example data:

set.seed(123)

tipos_exo <- data.frame(
  sample = rep(letters, each = 2),
  variable = c("tablaq_readsPerc", "tablaq_shortReadsPerc"),
  value = runif(52, 0, 100),
  batch = rep(LETTERS, each = 2)
)

library(ggplot2)
library(patchwork)
library(dplyr, warn = FALSE)

p1 <- ggplot(tipos_exo,aes(x = reorder(sample, -value),y = value,fill = variable))  
  geom_bar( stat = "identity")  
  scale_y_continuous(expand = c(0, 0))  
  labs(x = NULL)  
  theme(axis.text.x = element_blank(),
        axis.ticks.x = element_blank(),
        axis.ticks.length.x = unit(0, "pt"))

tipos_exo1 <- tipos_exo |> 
  mutate(sample = reorder(sample, -value)) |> 
  distinct(sample, batch)

p_axis <- ggplot(tipos_exo1, aes(x = sample, y = factor(1), fill = batch))  
  geom_tile(width = .9)  
  geom_text(aes(label = sample))  
  theme_void()  
  theme(axis.title.x = element_text())  
  labs(x = "Batch Annotation")  
  guides(fill = "none")

p1 / p_axis   plot_layout(heights = c(8, 1))