[R] Spatstat - K2 index

[Gough Lauren]

Hi all,

I'm using spatstat to investigate the spatial structure of an arid shrub
population.  The first-order intensity of my data does not appear to be
homogenous, so I would like to use inhomogeneous techniques.  I realise
there is a inhomogeneous K-function available in spatstat, but there
doesn't not appear to be one for the pair-correlation function (O-ring
statistic).  As such I was planning to use a new technique (the K2
index) as described in Schiffers et al. (2008) [Ecography, 31:545-555].
The following website has more detail
[http://www.oikos.ekol.lu.se/appendixdown/E5374-example.R].  Despite
this I cannot get the function to run!  I am not very familiar with R so
it is likely my problem is simple.  Does anyone have any experience with
the K2-index who can give me some pointers?

Many thanks

Lauren 

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