factor_plotting.R

# deps
library(magrittr)
library(dplyr)
library(ggplot2)
library(gridExtra)


# load data
data(iris)

# add in factor versions of the columns
#	Species is alphabetically ordered
#	Species2 is randomly ordered
iris %>% mutate(
  Species=factor(Species),
  Species2=factor(Species, levels=c("virginica", "setosa", "versicolor"))
) %>% group_by(
  Species,
  Species2
) %>% summarise(
  Sepal.Length=mean(Sepal.Length)
) -> meanDF

# make panels
p1=ggplot(meanDF, aes(x=Species, y=Sepal.Length)) + geom_bar(stat="identity") + ggtitle('default alphabetic order')
p2=ggplot(meanDF, aes(x=Species2, y=Sepal.Length)) + geom_bar(stat="identity")+ ggtitle('random order')

# make plots
grid.arrange(p1, p2, ncol=2)