seem (version 1.0)

Mat projection: Matrix projection

Description

Simulates structured population by projection matrix

Usage

sim.proj(t, x0, proj.mat, vars.plot, tunit, xunit, pdfout = F)

Arguments

t

projection times

x0

initial condition

proj.mat

projection matrix

vars.plot

variables to plot

tunit

units for time

xunit

units for population density

pdfout

switch to produce pdf files, (optional, default F)

Value

• x
  results for all age classes
• xp
  results for all age classes, as proportion of total
• xs
  results for all age classes, as proportion of last class
• lambda
  ratio of two consecutive values of xtot
• xtot
  total population

Details

To perform the simulation, we write a loop for time to iterate the multiplication of the matrix proj.mat by the state vector x. As time progresses in the loop, it calculates the total population xtot, the proportions xp in each class with respect to the total, and an approximation lambda to the dominant eigenvalue as the ratio of the total population at adjacent times, and the population is scaled with respect to the last class. Note that the calculation of lambda is the ratio of current year to previous.

References

Acevedo M.F. 2012. Simulation of Ecological and Environmental Models. CRC Press.

See Also

Simulation functions sim.comp, sim.mruns, sim.rnum, sim

Examples

P <- matrix(c(0,2,3, 0.5,0,0, 0,0.5,0), byrow=TRUE, ncol=3)
x0 <- c(100,50,25); xunit="(Indiv)"
t=seq(0,10,1); tunit="(Year)"
x <- sim.proj(t, x0, P, vars.plot=c(1:3),tunit, xunit)