I tried to look at whether there is cluster of psychiatric patients in a county. I have census tract data with a column showing how many psychiatric patients are there in a census tract. There are many (more than a half) census tracts without any psychiatric patients.
I used both fixed distance band and spatial weights matrix to do the hot spot analysis. When used fixed distance band, I used spatial auto correlation to generate the distance, and I chose the max peak, (because the when first peak occured, some features had no neighbor). Both fixed distance band and spatial weights matrix methods yielded the similar result (tracts with 0 value were marked as hot spots).
When examine the result, I found that many polygons marked as hot spot were actually with 0 value, which should have been cold spots. I understand that hotpost analysis calculates the values within a certain defined areas instead of the original polygons, but still don't totally understand the result and how to explain it.