library(dplyr)
library(nycflights13)
result <- flights %>%
#将flights数据集传给下面的group_by函数
group_by(year, month, day) %>%
select(arr_delay, dep_delay) %>%
summarise(
arr = mean(arr_delay, na.rm = TRUE),
dep = mean(dep_delay, na.rm = TRUE)
) %>%
filter(arr > 30 | dep > 30)
head(result)
出现错误
Registered S3 method overwritten by 'dplyr':
method from
print.rowwise_df
����̼�������dplyr��
The following objects are masked from ��package:stats��:
filter, lag
The following objects are masked from ��package:base��:
intersect, setdiff, setequal, union
Adding missing grouping variables: year
, month
, day