[R] SPDEP Package, neighbours list for Moran's I on large grid dataset
Ben Haller
rhelp at sticksoftware.com
Fri Apr 22 15:08:16 CEST 2011
On Apr 22, 2011, at 2:07 AM, Laurent Jégou wrote:
> Hello, thank you very much for this solution, i'll try to adapt it to my problem, i think i'll be able to.
Great!
> By the way, i wrote about a "sliding-window" weight matrix, it's an expression used in satellite images processing, esp. convolution filters, meaning that the main matrix is not confronted to another one of the same dimensions, but to a much smaller one. The calculus is executed value by value (pixels on an image), centering the small matrix on each one, hence the name of sliding window.
Yeah, I'm familiar with the concept in general, but I don't see how you can really apply it to Moran's I calculations; the Moran's I value is, by definition, based on calculating the value for every point compared to every other point, and looking at only points within a smaller window risks getting a value that is not representative of the larger context. But if it makes sense to you in your application, then more power to you. :->
Ben Haller
McGill University
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