使用求和和和求平均值将行条件合并为一行

Question

我有一个如下所示的表：

周>年级持续时间[/tr>9090

学生ID		班级	单元
1	A	1	2	50
1		A	1	3	100	120
1		B	1	3	70	30
2		B	4	1	80	60
2		B	4	1	90	60
2		B	5	2	100

我希望这就是您想要的：

library(dplyr)
df %>%
  group_by(Student_ID, Class, Week) %>%
  summarise(Grade = weighted.mean(Grade, Units), 
            Duration = sum(Duration),
            Units = sum(Units)) %>%
  relocate(Units, .after = Week)

# A tibble: 4 x 6
# Groups:   Student_ID, Class [3]
  Student_ID Class  Week Units Grade Duration
       <int> <chr> <int> <int> <dbl>    <int>
1          1 A         1     5    80      210
2          1 B         1     3    70       30
3          2 B         4     2    85      120
4          2 B         5     2   100       90