chesnokovaa

Different spatial weights matrices generate the same Hot Spot output

Discussion created by chesnokovaa on Nov 1, 2012
Hi! I'm probably missing something, but would greatly appreciate any help.

I'm doing some exploratory Hot Spot analyses and as part of honing down on the best specification for this and future spatial analyses, have been playing around with distances/spatial weights/etc. Data: Pennsylvania, Census Tract aggregate data for smoking rates

As expected, depending on distance threshold (using zone of indifference option within the HS tool), output of HS tool varies. Great.

However, when I tried to add an additional feature to conceptualization of spatial relationship using Spatial Weights Matrix tool (namely having a min neighbor requirement in addition to the distance threshold), I no longer see the variation.

More specifically, the following parameters, while seem to be generating different spatial weights matrices, do not produce different HS maps:
1. Matrix I: threshold dist=5300ft; min 8 neighbors; inverse distance
2. Matrix II: threshold dist=11000ft; min 8 neighbors; inverse dist
3. Matrix III: threshold dist=22000ft; min 8 neighbors; inverse dist
4. Matrix IV: threshold dist=53000ft; min 8 neighbors; inverse dist

I would expect the results of the above iterations to be comparable to using Zone of Indifference conceptualization with the same threshold distances. But instead, the output is identical and is not at all comparable to Zone of Indifference results.

Thoughts?

Many thanks!!!

P.S. I'm happy to attach the actual matrix and map files if helpful

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