[prev in list] [next in list] [prev in thread] [next in thread]
List: r-sig-geo
Subject: Re: [R-sig-Geo] Comparing spatial point patterns - Syrjala test
From: Barry Rowlingson <b.rowlingson () lancaster ! ac ! uk>
Date: 2008-02-11 9:19:02
Message-ID: 47B01306.5030800 () lancaster ! ac ! uk
[Download RAW message or body]
jiho wrote:
> Thank you very much for this reference. However the problem it is
> dealing with is not really similar to the one I target. In this paper
> the authors assess the differences in positions of neurones in a 2D
> plane between three groups of patients, with replicates in each group.
> So the data of interest are the coordinates.
> In my case, the positions of sampling stations are fixed (and on a
> grid if that helps [1]) and I want to assess the differences in
> abundances of two groups at these positions. So the data of interest
> are the abundances (normalized to remove the effect of total
> population sizes), and more specifically, the way the abundances are
> distributed on these points. Maybe the subject of this email is not
> correctly stated then. I am not a native english speaker and when it
> comes to technical terms, it is even worse.
>
"Spatial Point Pattern Analysis" only refers to cases where the
locations of the points are 'interesting', which usually means they are
generated by a stochastic process - like tree locations in a natural
forest rather than rows of trees in a plantation.
Analysis of data that comes from spatial locations that are
'uninteresting' are another branch of statistics altogether. It will
probably end up being generalised linear modelling with
spatially-correlated errors, and how you deal with the correlations is
the interesting part.
See if you can write down a model for your data and include a
smoothly-varying spatial error term.... Then maybe we can find some R
code to solve it. I don't think we'll find it in Spatstat, which I think
is still exclusively spatial point pattern analysis. Have a look at
geoRglm maybe...
Barry
_______________________________________________
R-sig-Geo mailing list
R-sig-Geo@stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic