Dear Stata list,
Can I get programming advice how to create a NxN distance
matrix using the information on latitude and longitude.
Below is what I attempted to do in STATA, but it didn't
work. Would be great if I can get any advice on how to
improve this code.
Thanks,
Susan
****************************
qui set obs 1000
gen xcoord = uniform()*100
gen ycoord = uniform()*100
mkmat xcoord ycoord
local N=_N
scalar N = _N
matrix latlong= xcoord,ycoord
matrix D = J(`N',`N', 0)
* looping through the rows and columns of the matrix D, to
get distance pair for each observations
for(i = 1; i <=N; i++) {
for(j = 1; j<=N; j++) {
if (i!=j){
D[i,j]=
((xcoord[i]-xcoord[j]^2+(ycoord[i]-ycoord[j]^2)^0.5
}
}
}
*
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