Description Usage Arguments Details Value Author(s) References Examples
Calculates the direct and indirect pathways in a network, i.e. the total system cycled throughflow, Finn's cycling index and average pathlength,...
Based on Finn(1980) (and not Finn (1976))
1 |
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 |
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 |
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 list with the following items:
TSTC |
total system cycled throughflow. |
TSTS |
non-cycled throughflow. |
FCI |
Finn's cycling index (1980). |
FCIb |
revised Finn's cycling index, sensu Allesina and Ulanowicz, 2004. |
APL |
average pathlength, also known as Network Aggradation (Sum of APLc and APLs in Latham 2006). |
Karline Soetaert <karline.soetaert@nioz.nl>, Julius Kipyegon Kones<jkones@uonbi.ac.ke>
Finn JT. 1980. Flow analysis of models of the Hubbard Brook ecosystem. Ecology 61: 562-571.
Patten BC, Higashi M. 1984. Modified cycling index for ecological applications. Ecological Modelling 25: 69-83.
Patten BC, Bosserman RW, Finn JT, Cale WG. 1976. Propagation of cause in ecosystems. Patten BC, editor. Systems Analysis and Simulation in Ecology, vol. 4. Academic Press, New York. p457-579.
Allesina and Ulanowicz, 2004. Cycling in ecological netowrks: Finn's index revisited. Computational Biology and Chemistry 28, 227-233.
Kones, J.K., Soetaert, K., van Oevelen, D. and J.Owino (2009). Are network indices robust indicators of food web functioning? a Monte Carlo approach. Ecological Modelling, 220, 370-382.
1 2 3 4 5 6 7 8 9 | # The takapoto atoll network
PathInd(Takapoto, Import = "CO2",
Export = c("CO2", "Sedimentation", "Grazing"))
# Conesprings is the example set 1a from Latham 2006.
as.data.frame(
PathInd(Tij = Conesprings, Import = "Inflows",
Export = c("Export", "Dissipation"))
)
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