Piping allows you to take the output of one function and pipe it as the input of the next function. You can string along several pipes to form a single chain.

• R Command: %>%
• Described as: "and then".

Ex: say you want to apply functions h() and g() and then f() on data x. You can do

• f(g(h(x))) OR
• x %>% h() %>% g() %>% f()

This

• saves you from confusing nested parentheses
• emphasizes the sequential breaking down of tasks, making it more readable
• i.e. Do this then do this then do this then …

Pipes are always directed to the first argument of any function. The following three bits of R code do the same thing, extract all january flights:

library(nycflights13)
data(flights)

# Bit 1: No piping
filter(flights, month == 1)

# Bit 2: Piping. Note no comma
flights %>% filter(month == 1)

# Bit 3: Piping across multiple lines (preferred for legibility)
flights %>% 
  filter(month==1)