projection {lmf} | R Documentation |
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 |
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
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))