ade4 (version 1.2-2)

multispati.randtest: Multivariate spatial autocorrelation test (in C)

Description

This function performs a multivariate autocorrelation test.

Usage

multispati.randtest(dudi, listw, nrepet = 999)

Arguments

dudi

an object of class dudi for the duality diagram analysis

listw

an object of class listw for the spatial dependence of data observations

nrepet

the number of permutations

Value

• Returns an object of class randtest (randomization tests).

Details

We note X the data frame with the variables, Q the column weights matrix and D the row weights matrix associated to the duality diagram dudi. We note L the neighbouring weights matrix associated to listw. This function performs a Monte-Carlo Test on the multivariate spatial autocorrelation index : $$r = \frac{trace(X^{t}DLXQ)}{trace(X^{t}DXQ)}$$

References

Smouse, P. E. and Peakall, R. (1999) Spatial autocorrelation analysis of individual multiallele and multilocus genetic structure. Heredity, 82, 561--573.

See Also

dudi,listw

Examples

if (require(maptools, quiet = TRUE) & require(spdep, quiet = TRUE)) {
    data(mafragh)
    maf.xy <- mafragh$xy
    maf.flo <- mafragh$flo
    maf.listw <- nb2listw(neig2nb(mafragh$neig))
    s.label(maf.xy, neig = mafragh$neig, clab = 0.75)
    maf.coa <- dudi.coa(maf.flo,scannf = FALSE)
    multispati.randtest(maf.coa, maf.listw)
}