AscInd {NetIndices} | R Documentation |
Calculates measures of system growth and development: Ascendency, Overhead and Capacity for several (sub)networks.
AscInd(Flow=NULL, Tij=t(Flow), Import=NULL, Export=NULL, Dissipation=NULL)
Flow |
network matrix with Flow[i,j] the flow from i (row) to j (column); component positions in rows and columns must be the same; if present, rownames or columnnames denote the compartment names. |
Tij |
network matrix where connectance is from column j to row i; component positions in rows and columns must be the same ; if present, rownames or columnnames denote the compartment names. |
Import |
vector with either the *indices* or the *names* of
external compartmens from where flow enters the network; the
indices point to the column positions in Tij (and the
row positions in Flow).
|
Export |
vector with either the *indices* or the *names* of
external compartmens to where flow leaves the network; the
indices point to the row positions in Tij (and the
column positions in Flow).
|
Dissipation |
vector with either the *indices* or the *names* to
external compartments that dissipate flows (e.g. respiration); the
indices point to the row positions in Tij (and the column
positions in Flow).
|
The mathematical formulation of these indices can be found in the package vignette - vignette("NetIndices").
The PDF can be found in the subdirectory ‘doc’ of the NetIndices package.
A matrix with ascendency values (columns) for several subnetworks (rows).
The subnetworks (rows) are:
total |
network |
internal |
network (excluding flows from and to external) |
import |
flows |
export |
flows; this includes the usuable and unusable flows (i.e. +dissipation) |
dissipation |
flows |
asc |
the ascendency of the network, a measure of growth and development. |
overh |
the overhead of the network. |
cap |
the development capacity of the network, an upper bound on ascendency. |
ACratio |
the ratio of ascendency and capacity. |
Karline Soetaert <k.soetaert@nioo.knaw.nl>, Julius Kipyegon Kones<jkones@uonbi.ac.ke>
Latham LG. 2006. Network flow analysis algorithms. Ecological Modelling 192: 586-600.
Ulanowicz RE. 2000. Ascendency: a measure of ecosystem performacne. Jorgensen SE, Muller F, editors. Handbook of Ecosystem Theories and Management. Lewis Publishers, Boca Raton, p303-315.
Ulanowicz RE, Norden JS. 1990. Symmetrical overhead in flow networks. International Journal of System Science 21: 429-437.
# The takapoto atoll network AscInd(Takapoto,Import ="CO2", Export=c("CO2","Sedimentation","Grazing"), Dissipation="CO2") # Conesprings is the example set 1a from Latham 2006. as.data.frame(AscInd(Tij=Conesprings,Import="Inflows", Export=c("Export","Dissipation"),Dissipation="Dissipation"))