leslie.row1 {demogR}

leslie.row1

Description

A utility for calculating the first row of a Leslie matrix from vectors of interval survival probabilities and age-specific fertility rates.

Usage

leslie.row1(mx, px, L = NULL, SRB = 1.05, peryear = 5, one.sex = TRUE)

Arguments

mx

vector of age-specific fertilities (length=k)

px

vector of interval survival probabilities (length=k-1)

L

person-years lived in the first interval; default L=NULL in which case each element is multiplied by peryear*sqrt(px[1]), otherwise each element is multiplied by L.

SRB

sex ratio at birth; default SRB=1.05.

peryear

width of the age-class/projection interval

one.sex

should each element be reduced by a factor 1/(1+SRB)? default one.sex=TRUE.

Details

Calculates the first-row entries for a Leslie matrix. This utility is particularly useful for constructing simulated Leslie matrices.

Value

A vector of length k, where k is the rank of the projection matrix A.

See Also

leslie.matrix

Examples

## simulate survival values from a beta(9,1) distribution

px <- rbeta(10,9,1)

## simulate fertility values from a gamma(2,10) distribution with age
##   at first reproduction = 10

mx <- c(0,0,0,rgamma(8,2,10))
A <- odiag(px,-1)
Fx <- leslie.row1(mx,px)
A[1,] <- Fx