st: Re: Calculating and storing distances

[evan roberts <eroberts@hist.umn.edu>]

The previous code I submitted works fine for a limited number of 
observations. If there are more than 80 locations it will not work 
whereas the following will:
foreach var in id lat lon {
gen `var'2=.
}

save main, replace

qui desc
local max=r(N)

forvalues k=1(1)`max' {

        use main, clear
        replace id2=id[`k']
        foreach var in lat lon {
                replace `var'2=.
                replace `var'2=`var' if id==id2
                sort id2 `var'2
                replace `var'2 = `var'2[1]
                }

        save tmp`k', replace

}

forvalues k=1(1)`max' {
use main, clear
append using tmp`k'
save main, replace
erase tmp`k'.dta
}

drop if id2==.

Evan Roberts

------------
Evan Roberts
Minnesota Population Center and Department of History
University of Minnesota
<eroberts@pop.umn.edu>
www.pop.umn.edu/~eroberts  
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