projection {lmf}

The projection matrix

Description

Estimates the components of the projection matrix and constructs the matrix given data on fecundity and survival in a age-structured population.

Usage

procomp(a, uage)
promat(pc, nage)

Arguments

a

a data set with fecundity and survival of individuals with known age over several years. Each individual can be represented once a year.

uage

the unique age classes in the data set.

pc

a matrix with columns age, fecundity and survival, i.e. the output from running the function procomp.

nage

the number of unique age classes in the data set.

Details

This function was made for internal use in lmf, but can be applied as a standalone.

The data set needs to contain the columns recruits (number of female offspring), survival (1 if the individual survives to the next reproductive event and 0 if it dies) and age.

The contruction of the projection matrix is divided into two functions for ease of storing and handling the estimates.

Value

procomp returns a matrix with the components of the projection matrix having columns age, fecundity and survival, while promat takes the output from procomp and returns the projection matrix.

Author(s)

Thomas Kvalnes

References

Caswell, H. 2000. Matrix Population Models, 2nd edn. Sinauer, Sunderland, Massachusetts. Engen, S., Saether, B.-E., Kvalnes, T. and Jensen, H. 2012. Estimating fluctuating selection in age-structured populations. Journal of Evolutionary Biology, 25, 1487-1499.

See Also

eigenl

Examples

#Data set from Engen et al. 2012
data(sparrowdata)
#The uniue age classes
unique.age <- unique(sparrowdata$age)
#Estimate the components of the projection matrix
projection.components <- procomp(a = sparrowdata, uage = unique.age)
#View components
projection.components
#Set up the projection matrix
promat(pc = projection.components, nage = length(unique.age))