Используя данные примера вашей игрушки:
clear
input destination origin var varnew
0 111 124 .
111 111 671 168
0 222 623 .
222 222 768 865
end
list, abbreviate(15)
+-------------------------------------+
| destination origin var varnew |
|-------------------------------------|
1. | 0 111 124 . |
2. | 111 111 671 168 |
3. | 0 222 623 . |
4. | 222 222 768 865 |
+-------------------------------------+
expand 2 if varnew != .
sort origin destination
list, abbreviate(15)
+-------------------------------------+
| destination origin var varnew |
|-------------------------------------|
1. | 0 111 124 . |
2. | 111 111 671 168 |
3. | 111 111 671 168 |
4. | 0 222 623 . |
5. | 222 222 768 865 |
|-------------------------------------|
6. | 222 222 768 865 |
+-------------------------------------+
У меня работает следующее:
bysort origin: replace destination = -1 if destination[_n] == destination[_n+1] & !missing(varnew)
bysort origin: replace var = varnew if var[_n] == var[_n+1] & !missing(varnew)
list destination origin var, abbreviate(15)
+----------------------------+
| destination origin var |
|----------------------------|
1. | 0 111 124 |
2. | -1 111 168 |
3. | 111 111 671 |
4. | 0 222 623 |
5. | -1 222 865 |
|----------------------------|
6. | 222 222 768 |
+----------------------------+