group | p | p1 |
1 | 1 | 0 |
1 | 1 | 0 |
1 | 2 | 0 |
1 | 3 | 0 |
1 | 4 | 0 |
1 | 5 | 0 |
1 | 7 | 0 |
1 | 7 | 0 |
1 | 8 | 0 |
2 | 2 | 0 |
2 | 2 | 0 |
2 | 3 | 0 |
2 | 4 | 0 |
2 | 5 | 0 |
2 | 5 | 0 |
2 | 6 | 0 |
2 | 7 | 0 |
2 | 8 | 0 |
如上数据,我已经将数据分组从小到大排序了,现想找出每组第五个位置的值,然后去分组替代p1,达到以下效果,
group | p | p1 |
1 | 1 | 4 |
1 | 1 | 4 |
1 | 2 | 4 |
1 | 3 | 4 |
1 | 4 | 4 |
1 | 5 | 4 |
1 | 7 | 4 |
1 | 7 | 4 |
1 | 8 | 4 |
2 | 2 | 5 |
2 | 2 | 5 |
2 | 3 | 5 |
2 | 4 | 5 |
2 | 5 | 5 |
2 | 5 | 5 |
2 | 6 | 5 |
2 | 7 | 5 |
2 | 8 | 5 |
请问如何用命令实现,求各位大神帮助,跪谢。