popdemo (version 0.2-3)

Cohen.cumulative : Calculate Cohen's cumulative distance

Description

Calculate Cohen's cumulative distance metric for a given population projection matrix (PPM) model.

Usage

Cohen.cumulative(A, vector)

Arguments

A

a square, irreducible, non-negative numeric matrix of any dimension.

vector

a specified initial age/stage distribution of class vector or class matrix.

Value

Cohen's D1.

Details

Calculates the cumulative distance metric as outlined in Cohen (1979).

Cohen.cumulative will not work for reducible matrices and returns a warning for imprimitive matrices (although will not function for imprimitive matrices with nonzero imaginary components in the dominant eigenpair).

References

Cohen (1979) SIAM J. Appl. Math., 36, 169-175. Stott et al. (2011) Ecol. Lett., 14, 959-970.

Examples

    # Create a 3x3 PPM
    A <- matrix(c(0,1,2,0.5,0.1,0,0,0.6,0.6), byrow=TRUE, ncol=3)
    A

    # Create an initial stage structure
    initial <- c(1,3,2)
    initial

    # Calculate Cohen cumulative distance
    Cohen.cumulative(A, vector=initial)