Question when drawing a graph in r(dodge or geom_line)

Question

I want to express the frequency of each column (a,b,c,d,e) in a graph of (t) for each group. I don't know what to do. As shown in the figure, the data was selected in the form of a data frame, but I don't know what to do when I express it in the next graph. I tried to extract only the value for a with ggplot, but even this didn't work out. Is there a good way? Is there a way to express it with lines other than bar graphs? Help me.

Answer 1

You can use the following code:

df <- data.frame(t = c("m", "i", "j", "z"),
                 a = c(300, 20, 15, 500),
                 b = c(100, 44, 99, 320),
                 c = c(200, 57, 98, 17),
                 d = c(150, 52, 122, 666),
                 e = c(50, 89, 64, 68))

library(tidyverse)
library(reshape)
df %>%
  melt(id.vars = "t") %>%
  ggplot(aes(x = t, y = value, fill = variable)) +
  geom_col(position = "dodge") 

Output:

Answer 2

Pivot the data longer to merge all counts of columns a to e inside just one name and value column, which can be used as dimension aesthetics for ggplot:

library(tidyverse)

data <- tribble(
  ~t, ~a, ~b,
  "m", 300, 100,
  "i", 20, 44,
  "j", 15, 99
)

data %>%
  pivot_longer(-t) %>%
  ggplot(aes(t, value, fill = name)) +
  geom_col(position = "dodge")

^{Created on 2022-05-06 by the reprex package (v2.0.0)}