gen.time: Generation time

In strandCet: Estimation of Biological Parameters from Stranded Cetaceans

Description

Calculates the generation time for an age or stage-classified demographic projection matrix.

Usage

gen.time(A, peryear = 5)

Arguments

A	Demographic projection matrix.
peryear	Width of the age classes.

Details

Calculates the generation time (T) for an age or stage-classified demographic projection matrix using the identity:

Ro = exp(r*T)

where Ro is the net reproduction number and r is the intrinsic rate of increase = log(lambda).

Generation time is the amount of time that it takes a typical female to produce Ro offspring or, equivalently, the amount of time it takes a population growing with instantaneous rate r to increase by a factor of Ro.

Value

The generation time implied by the demographic projection matrix.

Note

Calls function calc.ro, which calculates $R_0$ from the fundamental matrix of the Markov transition matrix (Caswell 2001).

References

Keyfitz, N., and Caswell. H. (2005). Applied mathematical demography. 3rd ed. New York: Springer.

Caswell, H. (2001). Matrix population models: Construction, analysis, and interpretation. 2nd ed. Sunderland, MA: Sinauer.

Preston, S.H., Heuveline, P. and Guillot, F. (2001). Demography: Measuring and modeling population processes. Oxford: Blackwell.

See Also

calc.ro eigen.analysis

strandCet documentation built on May 1, 2019, 8:19 p.m.