我正在努力完成dplyr教程的介绍。我已经加载了所需的数据集，如下所示：
flights
# A tibble: 336,776 x 19
year month day dep_time sched_dep_time dep_delay arr_time sched_arr_time arr_delay carrier flight tailnum origin dest air_time distance
<int> <int> <int> <int> <int> <dbl> <int> <int> <dbl> <chr> <int> <chr> <chr> <chr> <dbl> <dbl>
1 2013 1 1 517 515 2 830 819 11 UA 1545 N14228 EWR IAH 227 1400
2 2013 1 1 533 529 4 850 830 20 UA 1714 N24211 LGA IAH 227 1416
3 2013 1 1 542 540 2 923 850 33 AA 1141 N619AA JFK MIA 160 1089
4 2013 1 1 544 545 -1 1004 1022 -18 B6 725 N804JB JFK BQN 183 1576
5 2013 1 1 554 600 -6 812 837 -25 DL 461 N668DN LGA ATL 116 762
# ... with 336,771 more rows, and 3 more variables: hour <dbl>, minute <dbl>, time_hour <dttm>
下面是使用str()命令的数据集的另一个视图。
> str(flights)
tibble [336,776 x 19] (S3: tbl_df/tbl/data.frame)
$ year : int [1:336776] 2013 2013 2013 2013 2013 2013 2013 2013 2013 2013 ...
$ month : int [1:336776] 1 1 1 1 1 1 1 1 1 1 ...
$ day : int [1:336776] 1 1 1 1 1 1 1 1 1 1 ...
$ dep_time : int [1:336776] 517 533 542 544 554 554 555 557 557 558 ...
$ sched_dep_time: int [1:336776] 515 529 540 545 600 558 600 600 600 600 ...
$ dep_delay : num [1:336776] 2 4 2 -1 -6 -4 -5 -3 -3 -2 ...
$ arr_time : int [1:336776] 830 850 923 1004 812 740 913 709 838 753 ...
$ sched_arr_time: int [1:336776] 819 830 850 1022 837 728 854 723 846 745 ...
$ arr_delay : num [1:336776] 11 20 33 -18 -25 12 19 -14 -8 8 ...
$ carrier : chr [1:336776] "UA" "UA" "AA" "B6" ...
$ flight : int [1:336776] 1545 1714 1141 725 461 1696 507 5708 79 301 ...
$ tailnum : chr [1:336776] "N14228" "N24211" "N619AA" "N804JB" ...
$ origin : chr [1:336776] "EWR" "LGA" "JFK" "JFK" ...
$ dest : chr [1:336776] "IAH" "IAH" "MIA" "BQN" ...
$ air_time : num [1:336776] 227 227 160 183 116 150 158 53 140 138 ...
$ distance : num [1:336776] 1400 1416 1089 1576 762 ...
$ hour : num [1:336776] 5 5 5 5 6 5 6 6 6 6 ...
$ minute : num [1:336776] 15 29 40 45 0 58 0 0 0 0 ...
$ time_hour : POSIXct[1:336776], format: "2013-01-01 05:00:00" "2013-01-01 05:00:00" "2013-01-01 05:00:00" "2013-01-01 05:00:00" ...
但是，当我尝试使用filter()命令过滤数据时，我会得到以下错误：
> filter(flights, dest == "DTW")
Error in filter(flights, dest == "DTW") : object 'dest' not found
我在这里错过了什么？
将数据管道传输到筛选函数数据%>%filter((。