第 3 章 篩選觀察值
- filter
找出1月1日的航班資料
flights %>% filter(month==1,day==1) ## # A tibble: 842 x 19
## year month day dep_time sched_dep_time dep_delay
## <int> <int> <int> <int> <int> <dbl>
## 1 2013 1 1 517 515 2
## 2 2013 1 1 533 529 4
## 3 2013 1 1 542 540 2
## 4 2013 1 1 544 545 -1
## 5 2013 1 1 554 600 -6
## 6 2013 1 1 554 558 -4
## 7 2013 1 1 555 600 -5
## 8 2013 1 1 557 600 -3
## 9 2013 1 1 557 600 -3
## 10 2013 1 1 558 600 -2
## # ... with 832 more rows, and 13 more variables:
## # arr_time <int>, sched_arr_time <int>,
## # arr_delay <dbl>, carrier <chr>, flight <int>,
## # tailnum <chr>, origin <chr>, dest <chr>,
## # air_time <dbl>, distance <dbl>, hour <dbl>,
## # minute <dbl>, time_hour <dttm>