是否有可以计算非数字列出现次数的 R 函数？

Question

我在计算分类列时遇到问题。提前致谢！

所以我有这个数据框：

Employee ID  Station
1001         Produce
1002         Pharmacy
1001         Frozen
1003

我想在数据框中添加一列来计算每个员工拥有多少个站点。

输出示例：

Employee ID      Station  Count
    1001         Produce  2
    1002         Pharmacy 1
    1001         Frozen   2
    1003                  0

Answer 1

包 dplyr 中的函数 count 就是为了这个：

library(tidyverse)

data <- tribble(
  ~Employee.ID, ~Station,
  1001L, "Produce",
  1002L, "Pharmacy",
  1001L, "Frozen",
  1003L, NA
)

counts <-
  data %>%
  filter(!is.na(Station)) %>%
  count(Employee.ID)

counts
#> # A tibble: 2 x 2
#>   Employee.ID     n
#>         <int> <int>
#> 1        1001     2
#> 2        1002     1

data %>%
  left_join(counts) %>%
  mutate(n = n %>% replace_na(0))
#> Joining, by = "Employee.ID"
#> # A tibble: 4 x 3
#>   Employee.ID Station      n
#>         <int> <chr>    <dbl>
#> 1        1001 Produce      2
#> 2        1002 Pharmacy     1
#> 3        1001 Frozen       2
#> 4        1003 <NA>         0

^{由 reprex package (v2.0.1)}

于 2021-12-08 创建

是否有可以计算非数字列出现次数的 R 函数？

Is there an R function that can count the occurrences of a non-numeric column?

r

count

dataframe