elas: Calculate elasticity matrix

In popdemo: Demographic Modelling Using Projection Matrices

Calculate elasticity matrix

Description

Calculate the elasticity matrix for a specified population matrix projection model using eigenvectors.

Usage

elas(A, eval = "max")

Arguments

A	a square, non-negative numeric matrix of any dimension
eval	the eigenvalue to evaluate. Default is eval="max", which evaluates the dominant eigenvalue (the eigenvalue with largest REAL value: for imprimitive or reducible matrices this may not be the first eigenvalue). Otherwise, specifying e.g. eval=2 will evaluate elasticity of the eigenvalue with second-largest modulus.

Details

elas uses the eigenvectors of A to calculate the elasticity matrix of the specified eigenvalue, see section 9.1 in Caswell (2001). Same method as elasticity in popbio but can also evaluate subdominant eigenvalues.

Value

A numeric (real or complex) matrix of equal dimension to A.

References

• Caswell (2001) Matrix Population Models 2nd ed. Sinauer.

See Also

Other PerturbationAnalyses: sens(), tfa_inertia(), tfa_lambda(), tfam_inertia(), tfam_lambda(), tfs_inertia(), tfs_lambda()

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) )

  # Calculate sensitivities of dominant eigenvalue
  elas(A)
  # Calculate sensitivities of first subdominant eigenvalue,
  # only for observed transitions
  elas(A, eval=2)

popdemo documentation built on April 12, 2025, 2 a.m.