rand.neutral {untb} | R Documentation |
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.
rand.neutral(J, theta=NULL, prob.of.mutate=NULL, string = NULL, pad = FALSE)
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. |
pad |
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). |
Uses the simulation method on page 289 of Hubbell (2001).
If pad
is TRUE
, and you set string
to
“extinct
”, things will break.
Robin K. S. Hankin
S. P. Hubbell 2001. “The Unified Neutral Theory of Biodiversity”. Princeton University Press.
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? plot(table(replicate(100,rand.neutral(10,theta=0.7,pad=TRUE)[2])))