问题
I have the following data:
id tests testvalue
1 A 4
1 B 5
1 C 3
1 D 3
2 A 3
2 B 3
3 C 3
3 D 4
4 A 3
4 B 5
4 A 1
4 B 3
I would like to change the above long data format into following wide data.
id testA testB testC testD index
1 4 5 3 3 1
2 3 3 . . 2
3 . . 3 4 3
4 3 5 . . 4
4 1 3 . . 5
I am trying
reshape wide testvalue, i(id) j(tests)
It gives error because there are no unique values within tests.
What would be the solution to this problem?
回答1:
You need to create an extra identifier to make replicates distinguishable.
clear
input id str1 tests testvalue
1 A 4
1 B 5
1 C 3
1 D 3
2 A 3
2 B 3
3 C 3
3 D 4
4 A 3
4 B 5
4 A 1
4 B 3
end
bysort id tests: gen replicate = _n
reshape wide testvalue, i(id replicate) j(tests) string
See also here for documentation.
来源：https://stackoverflow.com/questions/28839986/how-to-reshape-long-to-wide-data-in-stata