Generates a random bipartite web, based on r2dtable and lognormal marginal distributions.
Usage
genweb(N1 = 10, N2 = 30, dens = 2)
Arguments
N1
Number of species in the lower trophic level; or a vector of length 2 giving number of lower and higher trophic level species. Defaults to 10.
N2
Number of species in the higher trophic level. Ignored if N1 a vector of length 2. Defaults to 30.
dens
Interaction density, i.e.~how many interactions there shall be, on average, for each species. Defaults to 2 (the median observed interaction density in the NCEAS pollination webs).
Value
A matrix with N1 x N2 species.
encoding
latin1
Details
This function can be used to create simple, but not necessarily realistic, bipartite
webs for given dimensionality and interaction density. Marginal distributions are
assumed to be lognormal, mean and standard deviation are calculated from , and
(see code for details).