SI.micro {RGeostats} | R Documentation |
The microstructure index measures the relative importance of structural components that have a smaller scale than the sampling lag (including random noise).
SI.micro(db, h0, pol, dlim, ndisc)
db |
Name of the |
h0 |
Mean lag between samples. |
pol |
The |
dlim |
The limit distance for valuating a node, when migrating points on a grid for computing the covariogram. GiVEN IN THE PROJECTED SPACE UNITS. |
ndisc |
Discretization of the data area when constructing the defaulted grid. |
The microstructure index.
Function originally developped for the EU project Fisboat, DG-Fish, STREP no 502572. Authors: Woillez, M., and Rivoirard, J. (Geosciences/Mines-ParisTech)
Mathieu Woillez, Ifremer, 2013
Woillez, M., Poulard, J-C., Rivoirard, J., Petitgas, P., and Bez, N. 2007. Indices for capturing spatial patterns and their evolution in time, with application to European hake (Merluccius merluccius) in the Bay of Biscay. - ICES Journal of Marine Science, 64: 537-550. http://icesjms.oxfordjournals.org/content/64/3/537.abstract
Woillez, M., Rivoirard, J., and Petitgas, P. 2009. Notes on survey-based spatial indicators for monitoring fish populations. - Aquatic Living Resources, 22: 155-164. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8215490
# Load data rg.load(filename="Demo.hake.bob.db.data",objname="db.data") rg.load(filename="Demo.hake.bob.poly.data",objname="poly.data") projec.define(projection="mean",db=db.data) mic = SI.micro(db.data,h0=10,pol=poly.data,dlim=50,ndisc=400) cat("Microstructure Index = ",mic,"\n") rm(db.data,poly.data)