tabulate multiple columns and plot the frequencies

multiple_tabulate.R

library(dplyr)
data(Wage, package = "ISLR")


Wage %>% 
  mutate(wage_f = ntile(wage, 2)) %>%  # bin it
  group_by(wage_f, health, race) %>% 
  summarise(count = n()) %>% 
  ggplot(aes(x = factor(wage_f), y = count, fill = race)) + 
  geom_bar(stat = "identity") + 
  facet_wrap(~health)
  
# http://rpubs.com/sebastian_sauer/195378





Wage %>% 
  mutate(wage_f = ntile(wage, 2)) %>%  # bin it
  group_by(wage_f, health, race) %>% 
  summarise(count = n()) %>% 
  mutate(prop = count/sum(count)) %>% 
  select(-count) %>% 
  ggplot(aes(x = factor(wage_f), y = prop, fill = race)) + 
  geom_bar(stat = "identity") + 
  facet_wrap(~health)

# http://rpubs.com/sebastian_sauer/195379