Cómo reordenar diagramas de barras en ggplot2

Problema

Queremos reodernar las barras de un diagrama de barras creado con ggplot2. En nuestro ejemplo, se puede observar que las barras no están ni en orden ascendente o descendente.

library(tidyverse)
ggplot(df, aes(x = Position)) + geom_bar()

Data frame

df <- structure(list(Position = structure(c(3L, 3L, 1L, 1L, 1L, 2L), .Label = c("Defense", 
"Striker", "Zoalkeeper"), class = "factor"), Name = structure(c(2L, 
1L, 3L, 5L, 4L, 6L), .Label = c("Frank", "James", "Jean", "John", 
"Steve", "Tim"), class = "factor")), class = "data.frame", row.names = c(NA, 
-6L))

    Position  Name
1 Zoalkeeper James
2 Zoalkeeper Frank
3    Defense  Jean
4    Defense Steve
5    Defense  John
6    Striker   Tim

Solución

Una alternativa es usar reorder para reordenar los niveles del factor. En orden ascendente (n) o descendente (-n) en función del conteo de la columna Position.

• Orden ascendente

df %>%
  count(Position) %>%
  ggplot(aes(x = reorder(Position, n), y = n)) +
  geom_bar(stat = 'identity') +
  xlab("Position")

• Orden descendente

df %>%
  count(Position) %>%
  ggplot(aes(x = reorder(Position, -n), y = n)) +
  geom_bar(stat = 'identity') +
  xlab("Position")

Entradas relacionadas

• Cambiar el orden de un diagrama de barras apiladas con ggplot2

Referencias

• stackoverflow

How to reorder bar charts with ggplot2

Problem

We'd like to reorder the bars of a bar chart. In our example below, the bars are not plotted in ascending or descending order.

library(tidyverse)
ggplot(df, aes(x = Position)) + geom_bar()

Data frame

df <- structure(list(Position = structure(c(3L, 3L, 1L, 1L, 1L, 2L), .Label = c("Defense", 
"Striker", "Zoalkeeper"), class = "factor"), Name = structure(c(2L, 
1L, 3L, 5L, 4L, 6L), .Label = c("Frank", "James", "Jean", "John", 
"Steve", "Tim"), class = "factor")), class = "data.frame", row.names = c(NA, 
-6L))

    Position  Name
1 Zoalkeeper James
2 Zoalkeeper Frank
3    Defense  Jean
4    Defense Steve
5    Defense  John
6    Striker   Tim

Solution

An alternative is using reorder to order the levels of a factor. In ascending (n) or descending order (-n) based on the count:

• Descending order

df %>%
  count(Position) %>%
  ggplot(aes(x = reorder(Position, -n), y = n)) +
  geom_bar(stat = 'identity') +
  xlab("Position")


• Ascending order

df %>%
  count(Position) %>%
  ggplot(aes(x = reorder(Position, n), y = n)) +
  geom_bar(stat = 'identity') +
  xlab("Position")

References

• stackoverflow