IPMpack (version 2.1)

predictFutureDistribution: Predicts continuous (e.g. size) stage distribution in the future giving current population's stage distribution.

Description

Function to project a population forwards using an IPM and a starting environment. The IPM may be structured by continuous (e.g. size) stage alone, or by continuous stage and environment.

Usage

predictFutureDistribution(startingSizes, IPM, n.time.steps, startingEnv = 1)

Arguments

startingSizes

vector containing the sizes of the desired starting population.

IPM

an IPMmatrix object (P matrix if only interested in survival projections, P matrix+ F matrix otherwise).

n.time.steps

a numeric defining the number of time steps for which projection is required.

startingEnv

vector defining the desired starting environment, of length one or length startingSizes; ignored if no environmental states are provided; otherwise if the length is less than startingSizes assumes all individuals start in the same environment, given by startingEnv[1].

Value

n.new.dist0

starting frequency distribution along meshpoints in IPMmatrix.

n.new.dist

final frequency distribution.

Details

Currently this does not accept IPMs with discrete stages (e.g. seedbank).

Examples

# Define starting population of interest
startPop <- rnorm(1000,2,1)

# Build T and F matrix
dff <- generateData()
Pmatrix <- makeIPMPmatrix(minSize = 1.1*min(dff$size, na.rm = TRUE),
maxSize = 1.1*max(dff$size, na.rm = TRUE), growObj = makeGrowthObj(dff),
survObj = makeSurvObj(dff), correction = "constant")
Fmatrix <- makeIPMFmatrix(minSize = 1.1*min(dff$size, na.rm = TRUE),
maxSize = 1.1*max(dff$size, na.rm = TRUE), 
fecObj = makeFecObj(dff, fecConstants = data.frame(est=0.7), Transform="log"), 
correction="constant")

# Make an IPMmatrix object containing P matrix + F matrix 
# by replacing the P matrix
IPM <- Pmatrix
IPM@.Data <- Pmatrix + Fmatrix

# Project population five steps
a5 <- predictFutureDistribution(startingSizes = startPop, IPM = IPM,
n.time.steps = 5, startingEnv = 1)