phi {untb} | R Documentation |
Ecosystem diagnostics such as Hubbell's phi and species count
phi(x,addnames=TRUE) no.of.spp(x) no.of.ind(x) no.of.singletons(x) singletons(x) simpson(x)
x |
Ecosystem vector; is coerced to class count |
addnames |
In function phi() , Boolean with default
TRUE meaning to set the name of the ith element
to the species with abundance i if unique. Set to
FALSE to suppress this, which is useful if the species names
are long |
Function phi()
coerces its argument to a count object and
by default returns a named vector whose ith element is the
number of species with i individuals. The name of the
ith element is the species with abundance i if unique
and empty otherwise. Function phi()
is used by
theta.prob()
.
Function no.of.spp()
returns the number of species in an
ecosystem object.
Function no.of.ind()
returns the number of individuals.
Function no.of.singletons()
returns the number of singletons.
Function singletons()
returns the names of the singletons.
Function simpson()
returns the Simpson index D: the
probability that two randomly sampled individuals belonging to
different species
The code for setting the names is a dog's breakfast
Robin K. S. Hankin
Hubbell
data(butterflies) phi(butterflies,add=FALSE) no.of.spp(butterflies) no.of.ind(butterflies) D <- simpson(butterflies) theta <- optimal.prob(butterflies)*2*no.of.ind(butterflies) #compare theta with D/(1-D) (should be equal): theta D/(1-D)