Statalist The Stata Listserver


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: RE: help expanding the dataset by n observations


From   Scott Cunningham <scunning@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: RE: help expanding the dataset by n observations
Date   Fri, 24 Nov 2006 11:06:44 -0500

On Nov 24, 2006, at 10:57 AM, Nick Cox wrote:

No, no, no. You want extra observations.
Try my advice. It should take about two minutes.
-reshape- is wonderful, but not the answer here.
Really? It is making extra observations. I have to reshape first long, generate the variables with the missing data, then reshape back, but it worked. Here's what I did. Here's a sample slice of my dataset:

+-----------------------------+
| county fip year vbl |
|-----------------------------|
1. | 1 1 1980 . |
2. | 1 1 1981 . |
3. | 1 1 1982 . |
4. | 1 1 1984 . |
5. | 1 1 1985 . |
|-----------------------------|
6. | 1 1 1987 . |
7. | 1 1 1988 . |
8. | 1 1 1991 . |
9. | 1 1 1992 . |
10. | 1 1 1995 . |
|-----------------------------|
11. | 1 1 1996 . |
12. | 1 1 1999 . |
13. | 1 1 2000 . |
14. | 3 1 1980 1 |
15. | 3 1 1981 1 |
|-----------------------------|
16. | 3 1 1982 1 |
17. | 3 1 1984 0 |
18. | 3 1 1985 0 |
19. | 3 1 1987 0 |
20. | 3 1 1988 0 |
|-----------------------------|
21. | 3 1 1991 0 |
22. | 3 1 1992 0 |
23. | 3 1 1995 0 |
24. | 3 1 1996 0 |
25. | 3 1 1999 0 |
|-----------------------------|
26. | 3 1 2000 0 |
+-----------------------------+


. egen id=group(county fip)
. reshape wide vbl, i(id) j(year)
. gen vbl1983=.
. gen vbl1986=.
...
. gen vbl2004=.
. reshape long vbl, i(id) j(year)
. list

+----------------------------------+
| id year county fip vbl |
|----------------------------------|
1. | 1 1980 1 1 . |
2. | 1 1981 1 1 . |
3. | 1 1982 1 1 . |
4. | 1 1983 1 1 . |
5. | 1 1984 1 1 . |
|----------------------------------|
6. | 1 1985 1 1 . |
7. | 1 1986 1 1 . |
8. | 1 1987 1 1 . |
9. | 1 1988 1 1 . |
10. | 1 1989 1 1 . |
|----------------------------------|
11. | 1 1990 1 1 . |
12. | 1 1991 1 1 . |
13. | 1 1992 1 1 . |
14. | 1 1993 1 1 . |
15. | 1 1994 1 1 . |
|----------------------------------|
16. | 1 1995 1 1 . |
17. | 1 1996 1 1 . |
18. | 1 1997 1 1 . |
19. | 1 1998 1 1 . |
20. | 1 1999 1 1 . |
|----------------------------------|
21. | 1 2000 1 1 . |
22. | 1 2001 1 1 . |
23. | 1 2002 1 1 . |
24. | 1 2003 1 1 . |
25. | 1 2004 1 1 . |
|----------------------------------|
26. | 2 1980 3 1 1 |
27. | 2 1981 3 1 1 |
28. | 2 1982 3 1 1 |
29. | 2 1983 3 1 . |
30. | 2 1984 3 1 0 |
|----------------------------------|
31. | 2 1985 3 1 0 |
32. | 2 1986 3 1 . |
33. | 2 1987 3 1 0 |
34. | 2 1988 3 1 0 |
35. | 2 1989 3 1 . |
|----------------------------------|
36. | 2 1990 3 1 . |
37. | 2 1991 3 1 0 |
38. | 2 1992 3 1 0 |
39. | 2 1993 3 1 . |
40. | 2 1994 3 1 . |
|----------------------------------|
41. | 2 1995 3 1 0 |
42. | 2 1996 3 1 0 |
43. | 2 1997 3 1 . |
44. | 2 1998 3 1 . |
45. | 2 1999 3 1 0 |
|----------------------------------|
46. | 2 2000 3 1 0 |
47. | 2 2001 3 1 . |
48. | 2 2002 3 1 . |
49. | 2 2003 3 1 . |
50. | 2 2004 3 1 . |
+----------------------------------+

Then I need to code the missing values (omitted here). This solution works with many different counties, and so seemed more efficient than going through -edit-. *
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/




© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index