stability.value | R Documentation |
Computes resilience of the system through Jacobian matrix eigenvalues.
stability.value(
val.mat,
biomasses,
efficiencies,
metabolic.types,
ef.level = "prey",
full.output = FALSE
)
val.mat |
A matrix describing fluxes between species (usually a result of |
biomasses |
A vector of species biomasses. |
efficiencies |
A vector or an array of conversion efficiencies of species in the adjacency matrix. These values describe the proportion of consumed energy that is converted to biomass of the consumer. |
metabolic.types |
A vector containing information on species type ( |
ef.level |
Set to |
full.output |
Logical, if |
efficiencies
: Determines how efficient species are to convert energy (see ef.level
for more details).
Providing an array will assume values depending on both prey and predator identity.
ef.level
: If "prey"
(resp "pred"
), the total amount of energy that can be metabolized from a trophic link
will be determined by prey (resp pred) identity. "link.specific"
assumes that efficiencies are defined for each trophic interaction
and implies efficiencies
parameter to be a matrix
full.output
: If TRUE
, function result is a list of eigenvalues and eigenvectors of the Jacobian matrix.
Maximum eigenvalue of the Jacobian matrix of a Lotka Voltera like system of equations. If full.output, Jacobian eigenvalues and eigenvectors are returned.
Benoit Gauzens, benoit.gauzens@gmail.com
losses = 0.15 * groups.level$bodymasses^(-0.25)
# define metbolic types:
met.types = rep('animal', length(losses))
met.types[groups.level$efficiencies == 0.545] = 'plant'
val.mat = fluxing(groups.level$mat,
groups.level$biomasses,
losses,
groups.level$efficiencies,
bioms.pref = TRUE,
ef.level = "pred")
stability.value(val.mat,
groups.level$biomasses,
groups.level$efficiencies,
metabolic.types = met.types,
ef.level = "pred")
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