根据https://dplyr.tidyverse.org/reference/tally.html，运行以下代码：
# Change the name of the newly created column:
species <-
starwars %>%
count(species, homeworld, sort = TRUE, name = "n_species_by_homeworld")
species
应该产生：
#> # A tibble: 58 x 3
#> species homeworld n_species_by_homeworld
#> <chr> <chr> <int>
#> 1 Human Tatooine 8
#> 2 Human <NA> 5
#> 3 Human Naboo 5
#> 4 Gungan Naboo 3
#> 5 Human Alderaan 3
#> 6 <NA> <NA> 2
#> 7 <NA> Naboo 2
#> 8 Droid <NA> 2
#> 9 Droid Tatooine 2
#> 10 Human Corellia 2
#> # … with 48 more rows
但是，我得到了：
# A tibble: 58 x 4
species homeworld name n
<chr> <chr> <chr> <int>
1 Human Tatooine n_species_by_homeworld 8
2 Human Naboo n_species_by_homeworld 5
3 Human NA n_species_by_homeworld 5
4 Gungan Naboo n_species_by_homeworld 3
5 Human Alderaan n_species_by_homeworld 3
6 Droid Tatooine n_species_by_homeworld 2
7 Droid NA n_species_by_homeworld 2
8 Human Corellia n_species_by_homeworld 2
9 Human Coruscant n_species_by_homeworld 2
10 Kaminoan Kamino n_species_by_homeworld 2
# ... with 48 more rows
帮助？
我正在跑步：
R版本3.5.0（2018-04-23）
平台：i386-w64-mingw32 / i386（32位）