st: Re: Automating generation of new vars from coordinated groups of inputvars.

["Michael Blasnik" <michael.blasnik@verizon.net>]

Something like this ought to work (haven't tested it yet):

foreach var of varlist *yr* {
local prefix=substr("`var'",1,index("`var'","yr")-1)
local suffix=substr("`var'",index("`var'","yr")+2,.)
gen int 
`prefix'dt`suffix'=mdy(`prefix'mo`suffix',`prefix'day`suffix',`var')
}
format *dt* %d

This approach will work with all vars that have yr somewhere in their name. 
If there are other variables that meet the *yr* spec that you don't want 
this done for, then it would be better to list out the *yr* variables that 
you want in the foreach line

Michael Blasnik
michael.blasnik@verizon.net


----- Original Message ----- 
From: "Clare L Maxwell" <maxwellcl1@earthlink.net>
To: <statalist@hsphsun2.harvard.edu>
Sent: Thursday, November 17, 2005 10:23 PM
Subject: st: Automating generation of new vars from coordinated groups of 
input vars.



> I have lots of dates I would like to calculate from month, day and year 
> variables.  It is a repetative task, and I would like to find a way to 
> automate it so that I would not have to write a gen command for each group 
> of variables.  Below is a partial list:
>
> "day" variables:  vday bday hivday cd4day rnday
>               hxday1 hxday2 bgday1 bgday2 endday1 endday2
>               lpday1 lpday2 cbday1 cbday2 ceday1 ceday2
> "month" variables: vmo bmo  hivmo  cd4mo rnmo
>               hxmo1 hxmo2 bgmo1 bgmo2 endmo1 endmo2
>               lpmo1 lpmo2 cbmo1 cbmo2 cemo1 cemo2
> "year" variables: vyr byr  hivyr  cd4yr rnyr
>               hxyr1 hxyr2 bgyr1 bgyr2 endyr1 endyr2
>               lpyr1 lpyr2 cbyr1 cbyr2 ceyr1 ceyr2
> new "date" variables:  vdate bdate hivdt cd4dt rndt
>               hxdt1 hxdt2 bgdt1 bgdt2 enddt1 enddt2
>               lpdt1 lpdt2 cbdt1 cbdt2 cedt1 cedt2
>
> Goal:  compute dates from all these month, day and year variables without 
> writing a gen command for each set.
>
> I have more complicated repetative tasks that also use coordinated groups 
> of variables.  This seemed simplest to explain.  I hope if I find a way to 
> deal with the dates, I will be able to generalize it to similar repetative 
> situations.
>
> Thank you very much in advance for your help.
>
> Yours truly,
> Clare Maxwell 
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