Exercises

1. Restyle the following pipelines following the guidelines above.

flights|>filter(dest=="IAH")|>group_by(year,month,day)|>summarize(n=n(),
delay=mean(arr_delay,na.rm=TRUE))|>filter(n>10)

flights|>filter(carrier=="UA",dest%in%c("IAH","HOU"),sched_dep_time>
0900,sched_arr_time<2000)|>group_by(flight)|>summarize(delay=mean(
arr_delay,na.rm=TRUE),cancelled=sum(is.na(arr_delay)),n=n())|>filter(n>10)

Solution

flights |> # space before/ after pipe and the last thing on a line
  filter(dest == "IAH") |> # indent twice, space between operators
  group_by(year, month, day) |> # space after comma
  summarize( # nam
    n     = n(), # add spaces so that all the = line up
    delay = mean(arr_delay, na.rm = TRUE)
    ) |> 
  filter(n > 10)


flights |> 
  filter(
         carrier        == "UA", 
         dest           %in% c("IAH","HOU"),
         sched_dep_time > 900,
         sched_arr_time < 2000
         ) |> 
  group_by(flight) |> 
  summarize(
            delay = mean(arr_delay, na.rm=TRUE),
            cancelled = sum(is.na(arr_delay)),
            n = n()
            ) |> 
  filter(n > 10)