Here's an example of how this would work with points that have coordinates with values that are similar to those you showed in your example.Ĭode: * generate 10 points with coordinates similar to original post At those latitudes, the distance between one degree of latitude is about the same as the distance between one degree of longitude. The trick is to scale your coordinates so that they appear to be near the equator.

If you end up having to work with projected coordinates however, you can still use geonear to find the nearest neighbors. These are invariably inaccurate as you cannot represent a spheroid on a plane in a way that respect distances between points. If you can't get the coordinates back to lat/lon, then you will essentially be measuring distances on a map and not on the surface of the earth. That would require that you know what map projection was used to generate your coordinates. If these are projected coordinates (as opposed to latitude and longitude in decimal degrees), you can indeed convert them back to lat/lon (using some GIS software) and then use geonear (from SSC) to find the nearest neighbors.

There is no need to use Stata or any additional downloading steps to understand the following solution: The whole point of dataex is to prepare a small data example that people can play with in view of presenting a self-contained solution, with everything needed to understand it in the post. * reduce to observations within the desired distanceīysort id: keep if inrange(x_koord_0, x_koord-1, x_koord+1) & ///ĭrop *_0Again however, the solution does not include all the information needed to understand it because the nature of the data is not revealed without the extra step of downloading a copy of the data, running the example, or running the part of the example that loads the data in memory.

Sas geodist example