EnvInd {NetIndices} | R Documentation |
calculates the indices of homogenization, synergism index, dominance of indirect effects,... of a network
EnvInd(Flow=NULL, Tij=t(Flow), Import=NULL, Export=NULL, full=FALSE)
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) |
full |
if TRUE, also returns matrices |
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:
NAG |
Network aggradation = average path length |
HP |
Homogenization index |
BC |
Synergism |
ID |
Dominance of Indirect effects |
MN |
Mean of non-dimensional flow-matrix (N) |
MG |
Mean of direct flow-matrix (G) |
CVN |
Coefficient of variation of non-dimensional flow-matrix (N) |
CVG |
Coefficient of variation of direct flow-matrix (G) |
U |
Only if Full == TRUE: The Utility non-dimensional matrix |
N1 |
Only if Full == TRUE: The Integral non-dimensional Flow Matrix |
G |
Only if Full == TRUE: The Normalized direct flow (or transitive closure matrix) matrix |
Karline Soetaert <k.soetaert@nioo.knaw.nl>, Julius Kipyegon Kones<jkones@uonbi.ac.ke>
Patten BC, Barber MC, Richardson TH. 1982. Path analysis of a reservoir ecosystem model.
Fath BD, Patten BC. 1999. Review of the foundations of network environ analysis. Ecosystems 2: 167-179.
Fath BD, Patten BC. 1999. Quantifying resource homogenization using network flow analysis. Ecological Modelling 123: 193-205.
Patten BC, Higashi M. 1984. Modified cycling index for ecological applications. Ecological Modelling 25: 69-83.
Higashi M, Patten BC. 1989. Dominance of indirect causality in ecosystems. The American Naturalist 133: 288-302.
# The takapoto atoll network EnvInd(Takapoto,Import ="CO2", Export=c("CO2","Sedimentation","Grazing")) as.data.frame(EnvInd(Tij=Conesprings,Import="Inflows", Export=c("Export","Dissipation"))) EnvInd(Tij=Conesprings,Import="Inflows", Export=c("Export","Dissipation"),full=TRUE)