point.sim.crM0: Mark-Recapture Method M0 : Simulation

Description Usage Arguments Details Value See Also Examples

Description

This function simulates mark-recapture samples and estimates abundance and related parameters for each simulated samples using the mark-recpature model M0.

Usage

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        point.sim.crM0(pop.spec, survey.spec, design.spec, B = 99, init.N = -1, seed=NULL,
                       Chapmod = FALSE, numerical=TRUE, plot=FALSE)

Arguments

pop.spec

population specification; either an object of class 'population' or 'pars.population'

survey.spec

survey specification; an object of class 'pars.survey.cr'

design.spec

design specification; an object of class 'design.cr'

B

number of simulations required

init.N

starting value of N used by the maximum likelihood opitimisation routine (see point.est.crM0)

seed

Number passed to set.seed() to initialise random number generator

Chapmod

If TRUE, Chapman's modified estimator is used. Only works with 2 sample mark-recapture survey

numerical

If TRUE estimation is by numerical maximisation of the log likelihood function

plot

if TRUE, a histogram of the group abundance point estimates obtained from each sample is produced with true group abundance and the mean of the abundance estimates from the simulations displayed on the plot.

Details

This function simulates surveys from the observation model (using survey.spec) and if pop.spec is of class 'pars.population' from the state model (using pop.spec to generate new populations on each simulation).

Value

An object of class point.sim.crM0, with the following elements:

est

A results matrix, each row of which contains the following values:

Nhat.grp

MLE of group abundance

Nhat.ind

MLE of individual abundance (= Nhat.grp * Es)

Es

Estimate of mean group size (simple mean of observed group sizes)

phat

Estimate(s) of capture probability for the relevant model (try it and see)

log.Likelihood

Value of log-likelihood at MLE

res.Deviance

Residual deviance at MLE

AIC

Akaike's information criterion

true

The true (simulated) values of group abundance, animal abundance and mean group size

numerical

Equal to the argument 'numerical' passed to the function

init.N

Equal to the argument 'init.N' passed to the function

Chapmod

Equal to the argument 'Chapmod' passed to the function

random.pop

TRUE if population is randomised

random.design

TRUE if design is randomised

parents

Details of WiSP objects passed to function

created

Creation date and time

seed

Equal to the argument 'seed' passed to the function

See Also

setpars.population, setpars.survey.cr point.est.crM0, set.seed

Examples

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cr.reg<-generate.region(x.length=100, y.width=50)

cr.dens <- generate.density(cr.reg)
cr.poppars<-setpars.population(density.pop = cr.dens, number.groups = 100, size.method = "poisson",
                               size.min = 1, size.max = 5, size.mean = 1, exposure.method = "beta",
                               exposure.min = 2, exposure.max = 10, exposure.mean = 3,
                               exposure.shape = 0.5, type.values = c("Male","Female"),
                               type.prob = c(0.48,0.52))
cr.pop<-generate.population(cr.poppars)

cr.des<-generate.design.cr(cr.reg, n.occ = 4)
cr.survpars<-setpars.survey.cr(cr.pop, cr.des, pmin.unmarked=0.00001, pmax.unmarked=0.5, improvement=0.01)
cr.samp<-generate.sample.cr(cr.survpars)

#Randomise population and survey
cr.sim.M0<- point.sim.crM0(pop.spec=cr.poppars, survey.spec=cr.survpars, design.spec=cr.des, B = 99) 
summary(cr.sim.M0)
plot(cr.sim.M0)
plot(cr.sim.M0, type="hist")
plot(cr.sim.M0, type="box")

#Randomise survey only
cr.sim.M0<- point.sim.crM0(pop.spec=cr.pop, survey.spec=cr.survpars, design.spec=cr.des, B = 99) 
summary(cr.sim.M0)
plot(cr.sim.M0)

dill/wisp documentation built on May 15, 2019, 8:31 a.m.