Dear Jean,

I have no idea of how to solve this issue, but I suggest you write to the
authors of spatstat package. I think they could help you very much. Another
thing is that there was a threhead on this many times ago. May be that Alan
Swanson cold also help you.

http://finzi.psych.upenn.edu/R/Rhelp02a/archive/51226.html

Kind regards,

miltinho


On 2/9/08, jiho <jo.irisson@gmail.com> wrote:
>
> Dear Lists,
>
> At several stations distributed regularly in space[1], we sampled
> repeatedly (4 times) the abundance of organisms and measured
> environmental parameters. I now want to compare the spatial
> distribution of various species (and test wether they differ or not),
> or to compare the distribution of a particular organism with the
> distribution of some environmental variable.
> Syrjala's test[2] seems to be appropriate for such comparisons. The
> hamming distance is also used (but it is not associated with a test).
> However, as far as I understand it, Syrjala's test only compares the
> distribution gathered during one sampling event, while I have four
> successive repeats and:
> - I am interested in comparing if, on average, the distributions are
> the same
> - I would prefer to keep the information regarding the variability of
> the abundances in time, rather than just comparing the means, since
> the abundances are quite variable.
>
> Therefore I have two questions for all the knowledgeable R users on
> these lists:
> - Is there a package in which Syrjala's test is implemented for R?
> - Is there another way (a better way) to test for such differences?
>
> Thank you very much in advance for your help.
>
> [1] http://jo.irisson.free.fr/work/research_tetiaroa.html
> [2] http://findarticles.com/p/articles/mi_m2120/is_n1_v77/ai_18066337/pg_7
>
> Jean-Olivier Irisson
> ---
> UMR 5244 CNRS-EPHE-UPVD, 52 av Paul Alduy, 66860 Perpignan Cedex, France
> +336 21 05 19 90
> http://jo.irisson.free.fr/work/
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo@stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

	[[alternative HTML version deleted]]

