Bar graph with relative and cumulative frequency

Question

I’m trying to make a bar graph with the count on top of the bars and the relative and accumulated frequencies on the left and right sides respectively but I’m not getting it.

The data is:

dput(x2)
    c(1L, 5L, 3L, 3L, 5L, 3L, 4L, 1L, 2L, 2L, 7L, 3L, 2L, 2L, 3L, 
    3L, 2L, 1L, 5L, 4L, 4L, 3L, 5L, 2L, 6L, 2L, 1L, 2L, 5L, 5L, 5L, 
    3L, 6L, 4L, 5L, 4L, 6L, 7L)

The frequency distributions

table(x2)
x2
1 2 3 4 5 6 7 
4 8 8 5 8 3 2 

Relative frequencies

prop.table(table(x2))
x2
         1          2          3          4          5          6          7 
0.10526316 0.21052632 0.21052632 0.13157895 0.21052632 0.07894737 0.05263158 

What I’m trying to do is exactly like in the image below

Answer 1

This is solved with the package ggplot2. First of all, I build a data frame with everything that needs to be plotted, with names that have some meaning in this context:

dados <- c(1L, 5L, 3L, 3L, 5L, 3L, 4L, 1L, 2L, 2L, 7L, 3L, 2L, 2L, 3L, 
           3L, 2L, 1L, 5L, 4L, 4L, 3L, 5L, 2L, 6L, 2L, 1L, 2L, 5L, 5L, 5L, 
           3L, 6L, 4L, 5L, 4L, 6L, 7L)

dados.plot <- data.frame(table(dados), table(dados)/sum(table(dados)),
  cumsum(prop.table(table(dados))))
dados.plot <- dados.plot[, -3]
names(dados.plot) <- c("Categoria", "FreqAbsoluta", "FreqRelativa", 
  "FreqCumulativa")
dados.plot$FreqRelativa <- dados.plot$FreqRelativa*100
dados.plot
  Categoria FreqAbsoluta FreqRelativa FreqCumulativa
1         1            4    10.526316      0.1052632
2         2            8    21.052632      0.3157895
3         3            8    21.052632      0.5263158
4         4            5    13.157895      0.6578947
5         5            8    21.052632      0.8684211
6         6            3     7.894737      0.9473684
7         7            2     5.263158      1.0000000   

With the data frame dados.plot prepared, I create a bar chart with the column FreqRelativa. Next, I place the values of FreqAbsoluta above the graph bars. Finally, I use the function sec_axis to include a second axis. Note that I have made a transformation in the data of FreqCumulativa, so that the line ends at the same height as the maximum value of the bars. It was enough to take 100 (maximum value of FreqCumulativa) and divided by a maximum of FreqRelativa.

library(ggplot2)

ggplot(dados.plot, aes(x=Categoria, y=FreqRelativa)) +
  geom_bar(stat="identity") + 
  geom_line(aes(y=FreqCumulativa*max(FreqRelativa), group=1)) +
  labs(x="Categoria", y="Frequência Relativa (%)") + 
  geom_text(aes(label=FreqAbsoluta), vjust=-0.8) +
  scale_y_continuous(
    sec.axis=sec_axis(trans=~ .*100/(max(dados.plot$FreqRelativa)), 
    name = "Frequência Cumulativa (%)"))

Colors, captions and other chart features can be adjusted after a query to the ggplot2.