sim.occ {fossil} | R Documentation |
Simulated Species Occurrence data
Description
A function to simulate a species occurrence data set
Usage
sim.occ(total.species = 100, endemics = 0.1, regions = 3, locs = 30, avg.abund = 1)
Arguments
total.species |
The total number of species in the region (i.e. the number of rows in the result matrix) |
endemics |
The proportion of endemic species for the entire region |
regions |
The number of areas of endemicity |
locs |
The number of samples/locatlities per region of endemicity |
avg.abund |
The 'average' abundance of a species for any given sample |
Details
The function creates a matrix of $c$ rows of species (given by total.species
) with $n$ number of sample columns (where $n$ equals $regions*locs$). The given abundance of any species at a given sample is determined by a log normal distribution, with each species being randomly assigned a value from rnorm()
. The number of endemics for any given region is equal to $total.species*endemics/regions$. An endemic is conseidered to only occur within a given region, and all other non-ndemic species are considered to be 'cosmopolitan' and can occur in any region. The avg.abund
value affects how many species are recovered at a given site, and for any given run there are typically species that are not present in the sample but are present in the region.
Value
Returns a matrix of simulated species abundances per locality.
Author(s)
Matthew Vavrek
See Also
Examples
## create a dataset with 2 regions and 5 samples per region
sim.occ(regions=2, locs=5)