projectionD {popdemo}

Calculate projection distance

Description

Calculate projection distance for a population matrix projection model.

Usage

projectionD(A, vector)

Arguments

A

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

vector

a numeric vector or one-column matrix describing the age/stage distribution used to calculate the distance.

Details

projectionD (Haridas & Tuljapurkar 2007) is the difference between the reproductive value of a population with demographic distribution given by vector and the reproductive value of a population in stable state.

projectionD 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).

Value

Projection distance.

References

• Haridas & Tuljapurkar (2007) Ecol. Lett., 10, 1143-1153.

• Stott et al. (2011) Ecol. Lett., 14, 959-970.

See Also

Other DistanceMeasures: CohenD(), KeyfitzD()

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) )

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

  # Calculate projection distance
  projectionD(A, vector=initial)