Two point layers must be loaded into ArcMap in order to use this
tool. The point layers MUST be in projected coordinate system like UTM or SPC, not a
Geographic (Lat/Lon) coordinate system. If either of your point layers is an event theme and you are experiencing
problems, try making it a shapefile and trying again (right click on the
event theme in the Table of Contents, select Data, then Export Data).
Selected a unique ID field
When you select a point layer from the drop-down box, all possible unique ID (UID)
fields are listed in the next drop-down box. A UID field will ideally be an integer field,
although the tool can accomodate text (string) fields. Given the choice, select an integer
Using only selected features.
When you select a point layer from the drop down list the program checks to see if
there are selected features in that layer, and enables the "Use selected features
only" option. If you select this option then only the selected features will be
Listing nearest neighbours.
Use the "Find the top N closest points" number box to define how many points
will be listed. If you select just 1 point, then all that will be listed is the single
closest point. If you select 5, then the top 5 closest points are listed in order of their
proximity, with the closest points always occuring first in the list (as you will be able
to see from the distances that are also output to that table). Note that in the case of
points that are equidistant, one of those points is selected arbitrarily as the closest.
If you have a large number of points (>100,000), this program may take a considerable amount of time
to run. It is recommended that you try running a test on a smaller sample before embarking on more ambitious analyses.