Dear R users,

I am conducting an analysis on disease spread in oak trees.  I have the
locations of symptomatic trees for two years (2004 and 2005) in an
irregularly-shaped polygon and want to know whether there is attraction or
repulsion between the two years.  The symptomatic trees are clustered within
a year.

I used Kcross to calculate the K statistic for my data and would like to
calculate simulation/confidence envelopes (for the univariate data, I used
Kenv).  I tried using Kenv.label, but based on my reading of the literature,
random labelling is not the appropriate test (see Goreaud and Pelissier,
2003, Journal of Vegetation Science).  I cannot use Kenv.tor because my
study area is not rectangular.

Next, I tried using this code:
kcross.envelope<-envelope(my.data, Kcross, correction="translate", nsim=99)

The result I get is reasonable, but I would like more information on how
'envelope' generates the envelopes (and how it labels the points) and
whether this is an appropriate test for my data.

Thanks,
Charlotte Reemts

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