# rand.neutral

0th

Percentile

##### Random neutral ecosystem

Given the size of the metacommunity $J$, and the fundamental biodiversity number $theta$, generate an object of class count using a stochcastic mechanism consistent with the neutral theory.

Keywords
math
##### Usage
rand.neutral(J, theta=NULL, prob.of.mutate=NULL, string = NULL, pad = FALSE)
##### Arguments
J
Size of metacommunity
theta
Fundamental biodiversity number $theta$. User must supply exactly one of theta and prob.of.mutate.
prob.of.mutate
Probability of mutation $nu$: $theta=2*J*nu$.
string
String to add to species names. By default (ie string being NULL), species are named “1”, “2”,$...$. Argument string supplies a prefix for these species names; a good one to use is “spp.”. This argument is useful because printing a count object can be confusing if the species names are all integers.
Boolean, with default FALSE meaning to return a count object having only extant species, and TRUE meaning to pad the count with extinct species to J species. Use this when a vector of length J is required consistently (see examples section).
##### Details

Uses the simulation method on page 289 of Hubbell (2001).

##### Note

If pad is TRUE, and you set string to “extinct”, things will break.

##### References

S. P. Hubbell 2001. “The Unified Neutral Theory of Biodiversity”. Princeton University Press.

untb

• rand.neutral
##### Examples
rand.neutral(1000, 9)
rand.neutral(1000, 9, string="spp.")

data(butterflies)
rand.neutral(no.of.ind(butterflies), optimal.theta(butterflies),string="spp.")

# what is the distribution of abundance of the second ranked species if
# J=10, theta=0.7?