`sf <- sf |> 

  dplyr::select(n_number, s_date) |> 

   dplyr::filter( s_date == mean(s_date), .by = n_number)`

There was 1 warning in dplyr::filter().ℹ In argument: s_date == mean(s_date).Caused by warning in mean.default():! argument is not numeric or logical: returning NA

I try to find out the first occurance date for each s_number.

The data is like this
| n_number | s_date |
| ——– | ——– |
| 1 | 2024-05-28 |
| 1 | 2024-05-25 |
| 2 | 2024-03-28 |
| 2 | 2024-04-25 |
| 3 | 2023-05-25 |

I want the output to like this

I tried to use dplyr filter to find the eariest date using mean() function, but it give the error above.