Hello! I am following along in an online textbook on how to use summarise / group_by. I came across the following from the nycflights13 data package:
by_day <- group_by(flights, year, month, day)
summarise(by_day, delay = mean(dep_delay, na.rm = TRUE))
In the textbook, it should yield the following:
#> Source: local data frame [365 x 4]_
#> Groups: year, month [?]_
#> _
#> year month day delay_
#> <int> <int> <int> <dbl>_
#> 1 2013 1 1 11.55_
#> 2 2013 1 2 13.86_
#> 3 2013 1 3 10.99_
#> 4 2013 1 4 8.95_
#> 5 2013 1 5 5.73_
#> 6 2013 1 6 7.15_
#> # ... with 359 more rows_
Instead, I get this................................
delay
1 12.63907
Further on in the textbook, I came across the following using the same nycflights13 data package:
by_dest <- group_by(flights, dest)
delay <- summarise(by_dest,
count = n(),
dist = mean(distance, na.rm = TRUE),
delay = mean(arr_delay, na.rm = TRUE)
)
delay <- filter(delay, count > 20, dest != "HNL")
In the console, I get this.........................................................................
by_dest <- group_by(flights, dest)
> delay <- summarize(by_dest,
+ count = n(),
+ dist = mean(distance, na.rm = TRUE),
+ delay = mean(arr_delay, na.rm = TRUE)
+ )
Error: This function should not be called directly
>
> delay <- filter(delay, count > 20, dest != "HNL")
Error in filter(delay, count > 20, dest != "HNL") :
object 'delay' not found
I updated all my packages but I cannot get past this point in the online book! I would appreciate any assistance and thank you in advance.
--G