assessComps: Assess stability effect of each compartment.
In dswdejonge/fwstability: Infer Food-Web Stability

View source: R/evaluate_characteristics.R

assessComps

R Documentation

Assess stability effect of each compartment.

Description

This function assesses the effect of removing individual compartments from the Jacobian matrix on stability.

Usage

assessComps(JM, method = "eigenvalue", MR = NULL, dead_names = NULL)

Arguments

`JM`	(required) A square named Jacobian matrix with numeric values representing the effect of one compartment (rows) on another compartment (columns).
`method`	(required) Either "eigenvalue" (default), "scalar", or "initial". The method "eigenvalue" finds asymptotic stability as the maximum real part of the eigenvalues calculated from the Jacobian matrix. The "scalar" method finds asymptotic stability as the scalar of natural mortality rates needed to acquire a stable matrix. The "initial" method finds initial stability as equation 4 from Arnoldi et al. (2016); initial stability is half the maximum real part of the eigenvalues derived from the matrix obtained by addition of the Jacobian matrix to its transpose.
`MR`	(required if method is "scalar") A named numeric vector containing mortality of the faunal compartments (per unit time, t-1). The values and names must be in the same order as the Jacobian matrix, and the values for dead compartments should be set to NA.
`dead_names`	(optional if method is "scalar") Character vector with all names of detritus and nutrient compartments (everything that is not fauna).

Details

If the change in stability (delta) is negative, the system becomes more stable if the respective food web compartment is removed from the Jacobian matrix. The opposite is true if delta is positive.
The 'scalar' method might be somewhat slower than the default 'eigenvalue' method.

Value

Returns a dataframe with absolute and relative changes in stability for removal of each food web compartment from the Jacobian matrix.

References

Neutel, A.M., Thorne, M.A.S., 2014. Interaction strengths in balanced carbon cycles and the absence of a relation between ecosystem complexity and stability. Ecol. Lett. 17, 651–661. https://doi.org/10.1111/ele.12266

dswdejonge/fwstability documentation built on Dec. 7, 2022, 7:24 p.m.