Is there a tool similar to the Average Nearest Neighbor tool where instead of calculating the average for the closest point it calculates the average for the closest X points?
Yes, you should use the Generate Near Table tool.
in_feature is the points feature you want to analyze.
near_feature is the points feature close/surrounding the point to analyze.
You must specify how far you want to limit the near table.
As a result you will have a table with the distance values from the point you want to evaluate to the n points that you are interested.
You can use any pivot table (excel works fine), or if you want more automated results you can use cursors to calculate the average distance.
Hope this helps.
Uncheck the box
Find only closest feature (optional) then enter the number of features to find in
Maximum number of closest matches (optional).
This will generate a table that has a
NEAR_RANK attribute you can query to get the values you need.
Sorry, but you are profoundly misunderstanding the tool/statistic. The nearest neighbor index (NNI) is a statistic for evaluating the spatial distribution of point observations, as to whether they are random or clustered.
This is one of the simplest indices in a family of statistics called Point Patten Analysis (PPA). The NNI tests the observed average neighbor distance against the expected and is not limited to a single neighbor, as you intimate. In fact, the average neighbor distance is calculated from a matrix of all pair-wise distances.
The Nearest Neighbor Index is calculated as:
Nearest Neighbor Distance (observed)
D(nn) = sum(min(Dij)/N)
Mean Random Distance (expected)
D(e) = 0.5 SQRT(A/N)
Nearest Neighbor Index
NNI = D(nn)/D(e)
Where; D=matrix of neighbor distances, A=Area, N=number of observations`