Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: Re: Trouble with -forval- and -gen- new variables


From   "Scott Merryman" <smerryman@kc.rr.com>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: Re: Trouble with -forval- and -gen- new variables
Date   Fri, 15 Aug 2003 15:10:43 -0500

How about

forval i = 1/52 {
gen time`i' = cond(group == `i',year - 74 ,0)
gen timep`i' = cond(group == `i', (year - 79)*(year >=80)  ,0)
}

Scott


----- Original Message -----
From: "Deborah Garvey" <DGarvey@scu.edu>
To: <statalist@hsphsun2.harvard.edu>
Sent: Friday, August 15, 2003 1:49 PM
Subject: st: Trouble with -forval- and -gen- new variables


> Hi, all.
>
> I hate to trouble the list with such a simple problem, but I can't figure out
what is wrong with my code.  I am attempting to generate a series of
state-specific and national time trends for a 12-year panel of data
using -forval- like an obedient Stata user instead of the now-defunct -for-
command.
>
> I am running Intercooled Stata 7.0 for Win98/95/NT (Born:  11 June 2002).
> Annotated log file follows:
>
> use "D:\school finance centralization\data\StatAbstract data\stateexpY7586";
>
> . keep fipsst pubst state tsrgex* rexcap* rgexed* rgexpw* rcapy* rpery*
> >  rexk12* k12pct* rppe*;
>
> . unab vars: *79;
>
> . local stubs: subinstr local vars "79" "", all;
>
> .  reshape long `stubs', i(fipsst) j(year);
> (note: j = 75 76 77 78 79 80 81 82 83 84 85 86)
> (note: k12pct75 not found)
> (note: rexk1275 not found)  -->  OK.  Missing exp data in 1975
> (note: rppe75 not found)
>
> Data                               wide   ->   long
> -----------------------------------------------------------------------------
> Number of obs.                       52   ->     624
> Number of variables                 108   ->      13
> j variable (12 values)                    ->   year
> xij variables:
>          k12pct75 k12pct76 ... k12pct86   ->   k12pct
>          tsrgex75 tsrgex76 ... tsrgex86   ->   tsrgex
>          rexcap75 rexcap76 ... rexcap86   ->   rexcap
>          rgexed75 rgexed76 ... rgexed86   ->   rgexed
>          rgexpw75 rgexpw76 ... rgexpw86   ->   rgexpw
>             rcapy75 rcapy76 ... rcapy86   ->   rcapy
>             rpery75 rpery76 ... rpery86   ->   rpery
>          rexk1275 rexk1276 ... rexk1286   ->   rexk12
>                rppe75 rppe76 ... rppe86   ->   rppe
> -----------------------------------------------------------------------------
>
> . gen lrppe = ln(rppe);
> (52 missing values generated)
>
> . egen group = group(fipsst), missing;
>
> . su group, meanonly;
>
> . di `r(max)';
> 52
>
> . forval i = 1/`r(max)' {
> >   gen time`i'= year - 74 if group == `i';
>   2.   gen timep`i' = (year - 79)*(year >=80) if group == `i';
>   3. };
> (612 missing values generated)
> [<<snip>> Repeated 104 times (=52 groups *2 vars)]
>
> Summing by group & year shows that time* and timep* are non-missing, valid
only for group 1.  For all other groups/year combinations, both variables are
missing (=51*12 = 612).
>
> . by group year: su time1 timep1 year fipsst;
>
> ____________________________________________________________
> -> group = 1, year = 75
>
>     Variable |     Obs        Mean   Std. Dev.       Min        Max
> -------------+-----------------------------------------------------
>        time1 |       1           1          .          1          1
>      timep1 |       1           0          .          0          0
>          year |       1         75          .         75         75
>         fipsst |       1           1          .          1          1
>
> <<snip>>
>
> What am I doing wrong?  It doesn't matter if I substitute the number of groups
(52) for the `rmax' saved result in the -forval- command.
>
> The program runs perfectly if I substitute -for- commands for the -forval-
loop:
> for num 1/`r(max)': gen timeX  = (year - 74)*(group == X);
> for num 1/52: gen timepX = (year - 79)*(group == X)*(year >=80);
>
> Thanks for any assistance you care to offer.
>
> Deb Garvey
>
>
> ******************************
> Deborah Garvey, Ph.D.
> Department of Economics
> Kenna Hall
> Santa Clara University
> Santa Clara, CA  95053
> 408/554-5580
> 408/554-2331 (FAX)
> dgarvey@scu.edu
> http://lsb.scu.edu/~dgarvey
> **********************************
>
>
> *
> *   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/


*
*   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