我有像这样的数据表x
+----+---------------+-------+
| id | arg | value |
+----+---------------+-------+
| 1 | New Day | NA |
| 2 | Eat breakfast | 3 |
| 3 | Bike | 45 |
| 4 | New Day | 0 |
| 5 | Get coffee | 1 |
| 6 | Exercise | 15 |
| 7 | Get beer | NA |
| 8 | New Day | |
| 9 | Pet cat | |
+----+---------------+-------+
我想为每天添加一个递增列来获得类似这样的内容
+----+---------------+-------+-----+
| id | arg | value | day |
+----+---------------+-------+-----+
| 1 | New Day | NA | 1 |
| 2 | Eat breakfast | 3 | 1 |
| 3 | Bike | 45 | 1 |
| 4 | New Day | 0 | 2 |
| 5 | Get coffee | 1 | 2 |
| 6 | Exercise | 15 | 2 |
| 7 | Get beer | NA | 2 |
| 8 | New Day | | 3 |
| 9 | Pet cat | | 3 |
+----+---------------+-------+-----+
我试过这个没有太大成功
x$day <-0
x<-within(x, day<-ifelse(arg == "New day", day+1, day))