loop.elas {demogR}

loop.elas

Description

Calculate and plot loop elasticities for a demographic projection matrix .

Usage

loop.elas(A, 
	       draw.plot = TRUE, 
	       peryear = 5, 
	       xlab = "Loop Elasticity", 
	       ylab = "Age", 
	       xlim = c(0, (maxe + 0.02)), 
	       ...)

Arguments

A

demographic projection matrix

draw.plot

should a plot be drawn? default: draw.plot=TRUE

peryear

width of the age-class/projection interval

xlab

x-axis label; default ylab="Age"

ylab

y-axis label; default ylab="Loop Elasticity"

xlim

plotting limits for x-axis

...

arguments to be passed to/from other methods

Details

Calculates and plots the life-cycle decomposition of van Groenendael et al (1994).

Value

A vector of length k (the rank of the projection matrix A) giving the loop elasticities for each of the loops in the life-cycle graph.

References

Van Groenendael, J., H. De Kroon, S. Kalisz, and S. Tuljapurkar. 1994. Loop analysis: Evaluating life history pathways in population projection matrices. Ecology 75 (8):2410-2415.

See Also

eigen.analysis, leslie.matrix

Examples

data(goodman)
ven <- with(goodman, life.table(x=age, nKx=ven.nKx, nDx=ven.nDx))
ven.mx <- with(goodman, ven.bx/ven.nKx)
A <- leslie.matrix(lx=ven$nLx,mx=ven.mx)

usa <- with(goodman, life.table(x=age, nKx=usa.nKx, nDx=usa.nDx))
usa.mx <- with(goodman, usa.bx/usa.nKx)
B <- leslie.matrix(lx=usa$nLx,mx=usa.mx)

eav <- eigen.analysis(A)
eau <- eigen.analysis(B)

## Compare the loop elasticities of Venezuela (1965) and the USA (1967)
le.usa <- loop.elas(A)
le.usa <- loop.elas(B)