Simulate posum data {posum}R Documentation

Population Surface Data Simulation

Description

population.data simulates stage structured population data from the model specified by rec and pcdr. Stages are really age classes, with the (lower) age boundaries specified in sim.age.bound.

Usage

population.data(t=(0:20)*5,ns=11,sc=1,fam="n",adult=FALSE)

sim.age.bound(stage,t)

Arguments

t The array of sample times at which simulated data are required (population.data) or the array of times at which stage age boundaries are required (sim.age.bound).
ns The number of stages.
sc The scale parameter for the noise to be added to the data.
fam Specifies the noise family as one of "n", "p", or "g", for normal, Poisson or gamma distributions.
adult TRUE to simulate an adult final stage (i.e. indeterminate duration), FALSE otherwise.
stage which stage the lower age boundary is required for.

Details

Stage populations are obtained by integrating the populaiton surface model given by population (and based on pcdr and rec) between the age limits specified in sim.age.bound. Noise is added according to the specified distribution and scale parameter. Integration is performed numerically using the trapezoidal rule.

Value

sim.age.bound returns an array of stage lower age boundaries.
population.data returns a list object suitable for input to posum. The items in this list are:

y array of simulated stage populations.
a0,a1 lower and upper age boundaries corresponding to the data in y.
t sample times corresponding to data in y.
stage stage index corresponding to data in y.

WARNING

Author(s)

Simon N. Wood snw@st-and.ac.uk

References

http://www.ruwpa.st-and.ac.uk/simon.html

See Also

death.surface, pcdr, population, population.surface, rec, survival,

Examples

data<-population.data(fam="p",adult=TRUE) #simulate data
b<-posum(data,fam="p")
op<-par(mfrow=c(2,2))
posum.plot(b)
plot(fitted(b),residuals(b))
plot(data$y,fitted(b))
par(mfrow=c(3,4))
posum.stage.plot(b)
posum.stage(b,lo=1,hi=4)
rm(data,b)
par(op)

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