Problem with visualizing top frequency Bar with desc() function

September 27, 2022

I am trying to visualize the top 3 or n bars in R in an order one after another. I have followed Question on stack overflow in which he did exactly the same what I want. In my dataset, I don’t have y-axis values where as desc() function requires one argument. I don’t know what argument should I pass in this desc() function which can give me the top 3 or n bars of a bar graph.

Mentioned below is my code and df. The first code for the bar graph works but not for the top 3 bars.

    values_1
1   C123
2   B323
3   C123
4   R333
5   R334
6   N123
7   U322
8   C123
9   U322
10  R444

Bars<- ggplot(df)+geom_bar(aes(x=values_1), bandwidth=0.5)+
ylab("Frequency")+xlab("My Values")
plot(Bars)

Code For top 3 Bars

df %>% 
    arrange(desc()) %>%
    slice(1:3) %>%
    ggplot(aes(x=values_1))+
              geom_bar()

Error

Error in arrange()
dec() must be called with exactly one argument.

>Solution :

We may need count

library(ggplot2)
library(dplyr)
df %>% 
   count(values_1, sort = TRUE) %>% 
   slice_head(n = 3) %>%
   mutate(values_1 = factor(values_1, levels = unique(values_1))) %>% 
   ggplot(aes(x = values_1, y = n)) +
    geom_col() + 
    ylab("Frequency")+
    xlab("My Values")

-output

data

df <- structure(list(values_1 = c("C123", "B323", "C123", "R333", "R334", 
"N123", "U322", "C123", "U322", "R444")), class = "data.frame",
 row.names = c("1", 
"2", "3", "4", "5", "6", "7", "8", "9", "10"))