[R] Dummy (factor) based on a pair of variables

[Bernardo Rangel Tura]

On Sat, 2009-04-18 at 08:55 +0200, Serguei Kaniovski wrote:
> 
> Dear All!
> 
> my data is on pairs of countries, i and j, e.g.:
> 
> y,i,j
> 1,AUT,BEL
> 2,AUT,GER
> 3,BEL,GER
> 
> I would like to create a dummy (indicator) variable for use in regression
> (using factor?), such that it takes the value of 1 if the country is in the
> pair (i.e. EITHER an i-country OR an j-country).
> 
> Thank you for your help,
> Serguei

Hi Serguei,

If I understand your doubt, the solution is something like this for pair
i-country is AUT or j-country is BEL


output ~ I(i-country=="AUT"|j-country=="BEL")
-- 
Bernardo Rangel Tura, M.D,MPH,Ph.D
National Institute of Cardiology
Brazil