Geonear error

[Cansu Oymak]

Dear Statalist users,

I have been trying to use geonear however, I keep receiving the following error. I do not understand the reason behind that. Can you please help me? Thanks a lot!


geonear ctr_n latitude longitude using "C:\Users\cansu\Dropbox\Data_Cansu\AB_data\Refugee s to match\Lat long refugee.dta", n(ctr_n1 Latbis Longbis)

latitude or longitude not constant within ctr_n group

Data1:

* Example generated by -dataex-. To install: ssc install dataex
clear
input str32 ctr_n double(latitude longitude)
"Benin"  12.10646 3.1050999
"Benin"  11.86819   3.38327
"Benin"  10.81281   2.72104
"Benin"  11.18131 2.2929499
"Benin"  12.10646 3.1050999
"Benin"  11.18131 2.2929499
"Benin"  10.81281   2.72104
"Benin"  11.72937   3.22174
"Benin"  10.72015   2.77878
"Benin"  10.81281   2.72104
"Benin"  11.86819   3.38327
"Benin"  11.08049    2.9061
"Benin"  10.72015   2.77878
"Benin"  11.72937   3.22174
"Benin"  11.13417 2.9386101
"Benin"  11.13417 2.9386101
"Benin"  11.29845   2.43856
"Benin"  11.86819   3.38327
"Benin"  10.78888   3.58459
"Benin"  10.78888   3.58459
"Benin"  11.23617   2.41646
"Benin"  11.18131 2.2929499
"Benin"  11.72937   3.22174
"Benin"  11.08049    2.9061
"Benin"  11.13417 2.9386101
"Benin"  10.72015   2.77878
"Benin"  11.72937   3.22174
"Benin"  12.10646 3.1050999
"Benin"  12.10646 3.1050999
"Benin"  11.86819   3.38327
"Benin"  11.08049    2.9061
"Benin"  12.10646 3.1050999
"Benin"  11.18131 2.2929499
"Benin"  12.10646 3.1050999
"Benin"  11.72937   3.22174
"Benin"  11.08049    2.9061
"Benin"  11.13417 2.9386101
"Benin"  11.18131 2.2929499
"Benin"  11.29845   2.43856
"Benin"  11.86819   3.38327
"Benin"  10.78888   3.58459
"Benin"  11.29845   2.43856
"Benin"  11.13417 2.9386101
"Benin"  11.23617   2.41646
"Benin"  11.23617   2.41646
"Benin"  11.08049    2.9061
"Benin"  11.86819   3.38327
"Benin"  10.72015   2.77878
"Benin"  11.72937   3.22174
"Benin"  11.29845   2.43856
"Benin"  11.29845   2.43856
"Benin"  12.10646 3.1050999
"Benin"  10.78888   3.58459
"Benin"  11.13417 2.9386101
"Benin"  11.18131 2.2929499
"Benin"  11.18131 2.2929499
"Benin"  11.29845   2.43856
"Benin"  11.13417 2.9386101
"Benin"  11.23617   2.41646
"Benin"  10.78888   3.58459
"Benin"  10.81281   2.72104
"Benin"  11.13417 2.9386101
"Benin"  11.08049    2.9061
"Benin"  10.81281   2.72104
"Benin"  11.23617   2.41646
"Benin"  10.72015   2.77878
"Benin"  10.72015   2.77878
"Benin"  11.23617   2.41646
"Benin"  11.86819   3.38327
"Benin"  11.08049    2.9061
"Benin"  11.23617   2.41646
"Benin"  11.86819   3.38327
"Benin"  10.81281   2.72104
"Benin"  11.29845   2.43856
"Benin"  11.72937   3.22174
"Benin"  11.23617   2.41646
"Benin"  10.72015   2.77878
"Benin"  10.81281   2.72104
"Benin"  11.08049    2.9061
"Benin"  10.78888   3.58459
"Benin"  10.81281   2.72104
"Benin"  11.18131 2.2929499
"Benin"  10.78888   3.58459
"Benin"  10.72015   2.77878
"Benin"  11.72937   3.22174
"Benin"  11.29845   2.43856
"Benin"  10.78888   3.58459
"Benin"  12.10646 3.1050999
"Benin"  10.30416   1.37962
"Benin"  10.69623 1.0630701
"Benin"  10.12554    1.4368
"Benin"  10.17711   1.10621
"Benin"  10.30416   1.37962
"Benin"      10.3   1.73333
"Benin"  10.40492    .94198
"Benin"  10.62118   1.26651
"Benin" 9.9956503   1.52147
"Benin"  10.35972   1.10782
"Benin"  10.84793   1.03711
"Benin"  10.82578   2.10479
end

Data2:

* Example generated by -dataex-. To install: ssc install dataex
clear
input str32 ctr_n1 double(Latbis Longbis)
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"               6.461        2.021
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.72748      1.76048
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Benin"             6.40764      1.88198
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Botswana"       -20.582222      26.4975
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Burkina Faso"      14.5981 -.7177780003
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
"Cameroon"     6.8074299996      14.1829
end

[Mike Lacy]

-geonear- is a user-written command available at SSC. It apparently expects that variables used as what it calls the "baseid" and "nborid" variables uniquely identify observations. How else could a program be expected to meaningfully match up observations in different files? Your ctr_n1 does not fulfill this condition in either your base or your neighbor file.

The solution is to create in each file a unique id variable. The best way to do that would depend on what other identifying variable(s) you have for the observations in each file. Let's suppose for illustration that the other identifying variable in each file is "city," a city name. With that, you could create and save a unique id variable for each observation (each place) in your two files like this:

gen idplace = ctr_n1 + "_"  + city

Then, your -geonear- command would use this new variable as the baseid and nborid.


Added: I overlooked the fact that multiple observations in your second file have the same latitude and longitude. That does not make sense for the current purpose, since that is information irrelevant and potentially confusing to -geonear-. You'd want to reduce that file to a single observation for each distinct location before using -geonear-.