There must be smarter ways to do this, but the one I came up is in the
following do file.
===========================
clear
set obs 4
gen country1="Paraguay"
replace country1="Italy" if _n==2
replace country1="Ghana" if _n==3
replace country1="Japan" if _n==4
tempvar id1 id2
gen `id1'=_n
local n=_N
forv i=1/`n' {
tempvar c`i'
gen `c`i''=country1[`i']
}
drop in `n'
expand `n'-_n
bysort `id1' : gen `id2'=`id1'+_n
gen country2=""
forv i=2/`n' {
replace country2= `c`i'' if `id2'==`i'
}
exit
===========================
Ichiro Fujikake
On 04.8.20 11:29, "Mark Manger" <[email protected]> wrote:
> Hi,
>
> I'm struggling with a data manipulation problem: I have a dataset with list
> of observations on a string variable and want to create pairwise
> combinations. My dataset looks like this:
>
> country1
> A
> B
> C
>
> I need the possible combinations so that the new dataset looks like
>
> country1 country2
> A B
> A C
> C B
>
> I could take the same list in two different datasets and then use the
> command "cross", but that gives me 3! combinations:
>
> AB AC BA BC CA CB
>
> For my purposes, AB and BA are identical. How do I create the list?
>
> Cheers,
>
> Mark
>
>
>
> Mark Manger
>
> University of British Columbia
> [email protected]
>
> *
> * For searches and help try:
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> * http://www.ats.ucla.edu/stat/stata/
>
*
* For searches and help try:
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* http://www.ats.ucla.edu/stat/stata/
