I am working with small datasets (around 100 points or less) with Nearest Neighbor Analysis in QGIS 2.8 (although I also tested in 2.6 and the result is the same). I have the layers referenced with a projected coordinate system.
When giving the results, I always get 0 as Observed Mean Distance, while Expected Mean Distance seems correct. I copy a typical output below:
Observed mean distance:0.0 Expected mean distance:367.212366515 Nearest neighbour index:0.0 N:98 Z-Score:-18.9384277177
Tested the same shapefile in other software and the value is valid (not 0). Is there any known limitation for the input shapefile? Any workaround?