The VARSTOCASES and CASESTOVARS commands
The below can also be performed using the [:FAQ/mixedR:RESTRUCTURE] command under the DATA menu in SPSS. For the example below we wish to stack columns x and y to make a single column called time. This is particularly useful for converting data from a format suitable for repeated measures to one suitable for multilevel modelling in SPSS. Notice we need to sort the cases before reformatting the data.
DATA LIST FREE / idno x y . BEGIN DATA 001 34 56 002 23 45 003 39 41 004 33 11 005 87 57 006 99 36 END DATA. SORT CASES BY IDNO. VARSTOCASES /MAKE time FROM x y /INDEX = newfact "new var label" (time) /KEEP = idno.
To do the reverse operation we need to use the CASESTOVARS command in conjunction with SORT CASES as below:
DATA LIST LIST/sub score.
BEGIN DATA
1 34
1 56
2 23
2 45
3 39
3 41
4 33
4 11
5 87
5 57
6 99
6 36
END DATA.
LIST.
COMPUTE num=1.
IF sub = LAG(sub) num = LAG(num)+1.
LIST.
SORT CASES BY sub num.
CASESTOVARS
/ID = sub
/INDEX = num.
LIST.