[R] attractive spatial point process?
Ben Bolker
ben at zoo.ufl.edu
Tue May 7 21:24:21 CEST 2002
I don't know if it's what you really want, but some variant of the
"Poisson cluster process" (where parents are randomly distributed in space
and "offspring" points are scattered around them according to some
distance distribution and in a random direction) might suit your purposes
(try Diggle 1973).
Ben
On Tue, 7 May 2002, James Marca wrote:
> Hi all,
>
> before I roll my own, naive implementation of a particular
> spatial point process, I thought I'd ask whether this has
> already been done.
>
> Specifically, I am looking for essentially the opposite of the
> Strauss and Mate'rn processes included in library(spatial) and
> documented in MASS. I am examining daily travel patterns, focusing
> on just the destinations of trips, not the movement itself. As
> people tend to go to the same places repeatedly, I think an
> appropriate spatial point process would be one which has a
> large probability of visiting the neighborhood of a prior point
> (but not the current point---this is a trip, after all), while at
> the same time having a non-zero probability of visiting a new point.
> Contrast this with the solid core/non-overlapping aspects of Strauss
> and SSI. Perhaps my process should be called SSA?
>
> Following the implementation of Strauss, I was going to parameterize
> the size of the points and the repeat/new probabilities, write
> a little C program, then see how the process K value compares to
> my collected data.
>
> A moderate-level search of R resources didn't
> turn up such a process already, and a Google search was equally
> useless (although this is perhaps due to my cluelessness regarding
> what to call this kind of process).
>
> Any pointers would be kindly appreciated, including "roll your
> own" and "read these refs."
>
> ---thanks in advance,
> James
>
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