R 计数条形图：具有大量计数的列和零或很少计数的列的倾斜数据

Question

The following code draws a barplot of count of x elements with y-axis in log scale.

library(ggplot2)  
library(scales)

myData <- data.frame(
  x = c(rep(1, 22500), 
        rep(2, 6000), 
        rep(3, 8000), 
        rep(4, 5000), 
        rep(11, 86), 
        rep(16, 15), 
        rep(31, 1), 
        rep(32, 1), 
        rep(47, 1))
)

ggplot(myData, aes(x=x)) + 
  geom_bar(width = 0.5)+
  geom_text(stat='count', aes(label = ..count..), vjust = -1, size=3)+
  scale_y_log10(breaks = trans_breaks("log10", function(x) 10^x),
                labels = trans_format("log10", math_format(10^.x)))+
  scale_x_continuous(breaks=(seq(1:47)))

Below is the plot:

My questions are:

1. How do I remove the x-axis tick marks/labels for those columns with zero count?

2. How do I show the values of column 31 , 32 , 47 better? (those with count 1)

3. How do I just label the count of the tallest column? ( 22500 of column 1 in this case)

Answer 1

One option would be for you to add a border color, which would help highlight that there is at least something in those parts of the graph:

library(tidyverse)

df <- 
  myData %>% 
  group_by(x) %>% 
  count()

df %>% 
  ggplot(aes(x = x, y = n)) +
  geom_col(color = "cyan4", fill = "cyan3") +
  geom_text(data = . %>% filter(x == 1), aes(label = n, y = n + 10000)) +
  scale_y_log10()