distance between two addresses (with latitude and longitude)

[River Huang]

Dear all, I ask this question for someone else (here in Chinese), The data is

* Example generated by -dataex-. To install: ssc install dataex
clear
input long stkcd int year str21(Jingwei1 Jingwei2)
2 2007 "114.068746,22.573589" "113.979272,22.562049"
2 2008 "114.068746,22.573589" "113.979272,22.562049"
2 2009 "114.068746,22.573589" "113.979272,22.562049"
2 2010 "114.068746,22.573589" "113.979272,22.562049"
2 2011 "114.068746,22.573589" "113.979272,22.562049"
2 2012 "114.068746,22.573589" "113.979272,22.562049"
2 2013 "114.068746,22.573589" "113.979272,22.562049"
2 2014 "114.068746,22.573589" "113.979272,22.562049"
2 2015 "114.068746,22.573589" "113.979272,22.562049"
2 2016 "114.068746,22.573589" "113.979272,22.562049"
2 2017 "114.068746,22.573589" "114.070184,22.552655"
2 2018 "114.068746,22.573589" "114.070184,22.552655"
2 2019 "114.068746,22.573589" "114.070184,22.552655"
2 2020 "114.068746,22.573589" "114.070184,22.552655"
4 2007 "114.054117,22.556835" "114.057334,22.54277"
4 2008 "114.054117,22.556835" "114.057334,22.54277"
4 2009 "114.054117,22.556835" "114.057334,22.54277"
4 2010 "114.054117,22.556835" "114.057334,22.54277"
4 2011 "114.054117,22.556835" "114.057334,22.54277"
4 2012 "114.054117,22.556835" "114.057334,22.54277"
end

The question is how to calculate the distance between `Jingwei1' (one address) and `Jingwei2' (the other address)? Thanks.

[Andrew Musau]

For geodetic distances, use geodist from SSC by Robert Picard. If you want distance by road, ask Google Maps. Distances are in kilometers. If you want miles, specify the -miles- option.

* Example generated by -dataex-. For more info, type help dataex
clear
input long stkcd int year str21(Jingwei1 Jingwei2)
2 2007 "114.068746,22.573589" "113.979272,22.562049"
2 2008 "114.068746,22.573589" "113.979272,22.562049"
2 2009 "114.068746,22.573589" "113.979272,22.562049"
2 2010 "114.068746,22.573589" "113.979272,22.562049"
2 2011 "114.068746,22.573589" "113.979272,22.562049"
2 2012 "114.068746,22.573589" "113.979272,22.562049"
2 2013 "114.068746,22.573589" "113.979272,22.562049"
2 2014 "114.068746,22.573589" "113.979272,22.562049"
2 2015 "114.068746,22.573589" "113.979272,22.562049"
2 2016 "114.068746,22.573589" "113.979272,22.562049"
2 2017 "114.068746,22.573589" "114.070184,22.552655"
2 2018 "114.068746,22.573589" "114.070184,22.552655"
2 2019 "114.068746,22.573589" "114.070184,22.552655"
2 2020 "114.068746,22.573589" "114.070184,22.552655"
4 2007 "114.054117,22.556835" "114.057334,22.54277"
4 2008 "114.054117,22.556835" "114.057334,22.54277"
4 2009 "114.054117,22.556835" "114.057334,22.54277"
4 2010 "114.054117,22.556835" "114.057334,22.54277"
4 2011 "114.054117,22.556835" "114.057334,22.54277"
4 2012 "114.054117,22.556835" "114.057334,22.54277"
end

split Jingwei1, p(,) g(coord1) destring
split Jingwei2, p(,) g(coord2) destring
rename (coord11-coord22) (lon1 lat1 lon2 lat2)
geodist lat1 lon1 lat2 lon2, g(wanted)

Res.:

. l stkcd year lon1-wanted, sepby(stkcd)

     +--------------------------------------------------------------------------+
     | stkcd   year        lon1        lat1        lon2        lat2      wanted |
     |--------------------------------------------------------------------------|
  1. |     2   2007   114.06875   22.573589   113.97927   22.562049   9.2903548 |
  2. |     2   2008   114.06875   22.573589   113.97927   22.562049   9.2903548 |
  3. |     2   2009   114.06875   22.573589   113.97927   22.562049   9.2903548 |
  4. |     2   2010   114.06875   22.573589   113.97927   22.562049   9.2903548 |
  5. |     2   2011   114.06875   22.573589   113.97927   22.562049   9.2903548 |
  6. |     2   2012   114.06875   22.573589   113.97927   22.562049   9.2903548 |
  7. |     2   2013   114.06875   22.573589   113.97927   22.562049   9.2903548 |
  8. |     2   2014   114.06875   22.573589   113.97927   22.562049   9.2903548 |
  9. |     2   2015   114.06875   22.573589   113.97927   22.562049   9.2903548 |
 10. |     2   2016   114.06875   22.573589   113.97927   22.562049   9.2903548 |
 11. |     2   2017   114.06875   22.573589   114.07018   22.552655   2.3229013 |
 12. |     2   2018   114.06875   22.573589   114.07018   22.552655   2.3229013 |
 13. |     2   2019   114.06875   22.573589   114.07018   22.552655   2.3229013 |
 14. |     2   2020   114.06875   22.573589   114.07018   22.552655   2.3229013 |
     |--------------------------------------------------------------------------|
 15. |     4   2007   114.05412   22.556835   114.05733    22.54277   1.5922887 |
 16. |     4   2008   114.05412   22.556835   114.05733    22.54277   1.5922887 |
 17. |     4   2009   114.05412   22.556835   114.05733    22.54277   1.5922887 |
 18. |     4   2010   114.05412   22.556835   114.05733    22.54277   1.5922887 |
 19. |     4   2011   114.05412   22.556835   114.05733    22.54277   1.5922887 |
 20. |     4   2012   114.05412   22.556835   114.05733    22.54277   1.5922887 |
     +--------------------------------------------------------------------------+

[River Huang]

Dear Andrew, Thanks for this helpful suggestion.