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From |
emanuele mazzini <madsoenistata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Loop year variable |

Date |
Sun, 21 Oct 2012 23:37:37 +0200 |

Ok, let's ignore this additional issue for the moment. I can be clearer I guess with the following example: +---------------------------------------------------------------------+ | year iso_o iso_d team_A team_B FT_A FT_B date_won | |---------------------------------------------------------------------| 1. | 1982 ITA DEU Italy Germany FR 3 1 1982 | 2. | 1983 ITA DEU . . . | 3. | 1984 ITA DEU . . . | 4. | 1985 ITA DEU . . . | 5. | 1986 ITA DEU . . . | |---------------------------------------------------------------------| 6. | 1987 ITA DEU . . . | 7. | 1988 ITA DEU . . . | 8. | 1989 ITA DEU . . . | 9. | 1990 ITA DEU . . . | 10. | 1991 ITA DEU . . . | |---------------------------------------------------------------------| 11. | 1992 ITA DEU . . . | 12. | 1993 ITA DEU . . . | 13. | 1994 ITA DEU . . . | 14. | 1995 ITA DEU . . . | +---------------------------------------------------------------------+ As you can see, the variable date_won is =1982 only for the year in which the match was played. Now, I would like to generate a new variable that would tell me how many years have gone by since Italy's last won (e.g, =0 for 1982, =1 for 1983, =2 for 1984, etc.). As I said, I tried with: gen yrs_won=year-date_won but this is the result: +---------+ | yrs_won | |---------| 1. | 0 | 2. | . | 3. | . | 4. | . | 5. | . | |---------| 6. | . | 7. | . | 8. | . | 9. | . | 10. | . | |---------| 11. | . | 12. | . | 13. | . | 14. | . | +---------+ As you can see, such command doesn't produce the expected result. That explains why I was looking for a way to expand the value of date_won for all cells. I thought that was the reason for the command not to work. Do you have any suggestion for overcoming my problem? Thank you in advance, Regards, E.M. 2012/10/21 Nick Cox <njcoxstata@gmail.com>: > I gathered from your original posting that you had yearly data. I > understand that matches may be more frequent than yearly, but I can't > advise further without seeing what your data look like as the trade > data and match data are not obviously compatible. > > Nick > > On Sun, Oct 21, 2012 at 1:00 PM, emanuele mazzini > <madsoenistata@gmail.com> wrote: >> Dear Mr Cox, >> >> thank you for your reply. The point, however, is that I cannot declare >> my dataset to be time-series (how would like but I cannot) due to the >> fact that some matches may take place once, twice or even more times >> in the same year. That is why I was looking form a manual command. I >> may better handle this first? And how can I do that in your opinion? >> >> Thanks in advance, >> >> E.M. >> >> 2012/10/21 Nick Cox <njcoxstata@gmail.com>: >>> This should yield to a treatment in terms of spells in the sense of >>> -tsspell- (SSC) and of >>> >>> SJ-7-2 dm0029 . . . . . . . . . . . . . . Speaking Stata: Identifying spells >>> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox >>> Q2/07 SJ 7(2):249--265 (no commands) >>> shows how to handle spells with complete control over >>> spell specification >>> >>> Look at -tsspell- first; it is self-contained. That is, your panels >>> are defined by country pairs (dyads) and the start of a spell is >>> defined by a match taking place (or a particular result; I don't >>> follow exactly what you want, e.g what about draws?). Then a variable >>> defined by -tsspell- gives you sequence in spell. You may need to >>> subtract 1. >>> >>> I don't see that loops are needed. >>> >>> Nick >>> >>> On Sun, Oct 21, 2012 at 12:07 PM, emanuele mazzini >>> <madsoenistata@gmail.com> wrote: >>> >>>> I am not a new Stata user, but I have to admit I still encounter some >>>> problems with writing loops. A loop may not be the solution to the >>>> issue I am going to describe, but I thought it is tough. >>>> >>>> I do have a dataset where I have country-pair trade observations for >>>> years 1950-2006 as well as another information, which is football >>>> match result for some dyads. I therefore need to generate a variable >>>> that indicates how many years are passed since the last won/lost of a >>>> country versus another. Suppose FT_A and FT_B are the final results >>>> for team A and B. I thought to generate a variable as follows: >>>> >>>> gen int date_won=year if FT_A>FT_B | FT_A<FT_B >>>> >>>> in order to get a variable that is = year for every observation I have >>>> information about, which reports the year of the won/loss. I then >>>> thought to generate another variable (let's say yrs_won) to tell me >>>> how many years have gone by as follows: >>>> >>>> gen int yrs_won=year-date_won >>>> >>>> Unfortunately, I do not get what I want: the only value yrs_won >>>> assumes is 0, but for all years from 1983 until 2006 I would like it >>>> to be 1, 2,3 and so on. >>>> >>>> At the beginning I didn't realize the problem, now it may be occur due >>>> to the fact that date_won = year only for the year in which the match >>>> was played. I guess I need to do something such as writing a loop to >>>> let it spread over all cells of such variable, but I don't really know >>>> how to make it. Does anyone of you has any suggestion? > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/statalist-faq/ > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: Loop year variable***From:*Nick Cox <njcoxstata@gmail.com>

**References**:**st: Loop year variable***From:*emanuele mazzini <madsoenistata@gmail.com>

**Re: st: Loop year variable***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Loop year variable***From:*emanuele mazzini <madsoenistata@gmail.com>

**Re: st: Loop year variable***From:*Nick Cox <njcoxstata@gmail.com>

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