st: programming: stopping loops?

["Claire M. Kamp Dush" <cmk54@cornell.edu>]

Hello, I feel embarrassed to post this because I am sure the answer to this 
is obvious, but I have been puzzling over this issue for a few hours.  I am 
trying to recode the family structure data in the NLSY 79 through 2004.  I 
am trying to go back and recode the data for missing years based on reports 
of marital changes between interviews at follow-ups.  For instance, if an 
individual was interviewed in 1991 and not in 1992, in 1993 they are asked 
to report up to 3 marital changes since the last time they were 
interviewed.  My data is stacked, with each individual having 26 lines of 
data, for years 1979 through 2004.  The id variable is momid and the year 
variable is year.  change1type, change2type, and change3type are measured 
each year where the respondent has data, and is a categorical variable with 
categories including married, divorced, separated, widowed, etc.  changey1_ 
, changey2_, and changey3_ are the years in which the each change is said 
to occur.  Here is an example of what the data look like:

momid   year    change1type     changey1_       change2type     changey2_
1               2000    Married         2000
1               2001
1               2002    Separated       2001            Divorced        2001
1               2003
1               2004
2               1988    Married 1987
2               1989
2               1990
2               1991
2               1992
2               1993
2               1994
2               1995
2               1996    Divorced        1993
2               1997
2               1998
2               1999
2               2000    Remarried       1998

My goal is to have my data look like the following:

momid   year    change1type     changey1_       change2type     changey2_ 
    change1misstype         change2misstype
1               2000    Married         2000 
            Married
1               2001 
            Separated               Divorced
1               2002    Separated       2001            Divorced        2001
1               2003
1               2004
2               1987 
            Married
2               1988    Married         1987
2               1989
2               1990
2               1991    Divorced        1991 
            Divorced                Remarried
2               1992    Remarried       1991
2               1993 
            Divorced
2               1994
2               1995
2               1996    Divorced        1993
2               1997
2               1998 
            Remarried
2               1999
2               2000    Remarried       1998


My first step in doing this was to create a series of variables, 
change1misstype through change6misstype (note that I have through 
change6misstype because there can be up to six changes reported in a given 
year).  I wrote the following two programs to cycle through my data, 
replacing these variables.  However, my problem is that I want it to stop 
replacing once one of my six variables takes on the value of change1type 
for a given year (or change2type or change3type).  I don't know how to stop 
it at that point.  I am very very new to programming, and to Stata, so I am 
sure that there is a better way I could be doing this.  Do I need to use 
else?  I was trying to figure this out, but any advice would be amazing.

Sincerely,
Claire Kamp Dush



**Program 1

global w = 1979

prog define recodechange
while $w < 2005 {
by momid: replace change1misstype = change1type if year == $w & year == 
changey1_ & change1type != . & change1misstype == .
by momid: replace change1misstype = change2type if year == $w & year == 
changey2_ & change2type != . & change1misstype == .
by momid: replace change1misstype = change3type if year == $w & year == 
changey3_ & change3type != . & change1misstype == .
by momid: replace change2misstype = change1type if year == $w & year == 
changey1_ & change1type != . & change1misstype != . & change2misstype == .
by momid: replace change2misstype = change2type if year == $w & year == 
changey2_ & change2type != . & change1misstype != . & change2misstype == .
by momid: replace change2misstype = change3type if year == $w & year == 
changey3_ & change3type != . & change1misstype != . & change2misstype == .
by momid: replace change3misstype = change1type if year == $w & year == 
changey1_ & change1type != . & change1misstype != . & change2misstype != . 
& change3misstype == .
by momid: replace change3misstype = change2type if year == $w & year == 
changey2_ & change2type != . & change1misstype != . & change2misstype != . 
& change3misstype == .
by momid: replace change3misstype = change3type if year == $w & year == 
changey3_ & change3type != . & change1misstype != . & change2misstype != . 
& change3misstype == .
by momid: replace change4misstype = change1type if year == $w & year == 
changey1_ & change1type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype == .
by momid: replace change4misstype = change2type if year == $w & year == 
changey2_ & change2type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype == .
by momid: replace change4misstype = change3type if year == $w & year == 
changey3_ & change3type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype == .
by momid: replace change5misstype = change1type if year == $w & year == 
changey1_ & change1type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype != . & change5misstype == .
by momid: replace change5misstype = change2type if year == $w & year == 
changey2_ & change2type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype != . & change5misstype == .
by momid: replace change5misstype = change3type if year == $w & year == 
changey3_ & change3type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype != . & change5misstype == .
by momid: replace change6misstype = change1type if year == $w & year == 
changey1_ & change1type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype != . & change5misstype != . & 
change6misstype == .
by momid: replace change6misstype = change2type if year == $w & year == 
changey2_ & change2type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype != . & change5misstype != . & 
change6misstype == .
by momid: replace change6misstype = change3type if year == $w & year == 
changey3_ & change3type != . & change1misstype != . & change2misstype != . 
& change3misstype != . & change4misstype != . & change5misstype != . & 
change6misstype == .
global w = $w + 1
}
end
recodechange



**Program 2

global w = 1979
global q = 1
global z = 26

prog define recodechange2
while $w < 2005 {
while $q < $z {
by momid: replace change1misstype = change1type[_n+$q] if year == $w & year 
== changey1_[_n+$q] & change1type[_n+$q] != . & change1misstype == .
by momid: replace change1misstype = change2type[_n+$q] if year == $w & year 
== changey2_[_n+$q] & change2type[_n+$q] != . & change1misstype == .
by momid: replace change1misstype = change3type[_n+$q] if year == $w & year 
== changey3_[_n+$q] & change3type[_n+$q] != . & change1misstype == .
by momid: replace change2misstype = change1type[_n+$q] if year == $w & year 
== changey1_[_n+$q] & change1type[_n+$q] != . & change1misstype != . & 
change2misstype == .
by momid: replace change2misstype = change2type[_n+$q] if year == $w & year 
== changey2_[_n+$q] & change2type[_n+$q] != . & change1misstype != . & 
change2misstype == .
by momid: replace change2misstype = change3type[_n+$q] if year == $w & year 
== changey3_[_n+$q] & change3type[_n+$q] != . & change1misstype != . & 
change2misstype == .
by momid: replace change3misstype = change1type[_n+$q] if year == $w & year 
== changey1_[_n+$q] & change1type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype == .
by momid: replace change3misstype = change2type[_n+$q] if year == $w & year 
== changey2_[_n+$q] & change2type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype == .
by momid: replace change3misstype = change3type[_n+$q] if year == $w & year 
== changey3_[_n+$q] & change3type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype == .
by momid: replace change4misstype = change1type[_n+$q] if year == $w & year 
== changey1_[_n+$q] & change1type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype == .
by momid: replace change4misstype = change2type[_n+$q] if year == $w & year 
== changey2_[_n+$q] & change2type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype == .
by momid: replace change4misstype = change3type[_n+$q] if year == $w & year 
== changey3_[_n+$q] & change3type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype == .
by momid: replace change5misstype = change1type[_n+$q] if year == $w & year 
== changey1_[_n+$q] & change1type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype != . & 
change5misstype == .
by momid: replace change5misstype = change2type[_n+$q] if year == $w & year 
== changey2_[_n+$q] & change2type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype != . & 
change5misstype == .
by momid: replace change5misstype = change3type[_n+$q] if year == $w & year 
== changey3_[_n+$q] & change3type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype != . & 
change5misstype == .
by momid: replace change6misstype = change1type[_n+$q] if year == $w & year 
== changey1_[_n+$q] & change1type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype != . & 
change5misstype != . & change6misstype == .
by momid: replace change6misstype = change2type[_n+$q] if year == $w & year 
== changey2_[_n+$q] & change2type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype != . & 
change5misstype != . & change6misstype == .
by momid: replace change6misstype = change3type[_n+$q] if year == $w & year 
== changey3_[_n+$q] & change3type[_n+$q] != . & change1misstype != . & 
change2misstype != . & change3misstype != . & change4misstype != . & 
change5misstype != . & change6misstype == .
global q = $q + 1
}
global z = $z - 1
global w = $w + 1
}
end
recodechange2





Claire M. Kamp Dush, Ph.D.
Postdoctoral Fellow, Evolving Family Theme Project
Cornell University
Bronfenbrenner Life Course Center
Bebee Hall
Ithaca, NY  14853
607-255-9908
http://www.socialsciences.cornell.edu/0407/evolv_fam_desc.html

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