multispati.randtest {ade4} | R Documentation

## 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

### 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 = trace(t(X)DLXQ) / trace(t(X)DXQ)

### Value

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

### Author(s)

Daniel Chessel chessel@biomserv.univ-lyon1.fr
Sébastien Ollier ollier@biomserv.univ-lyon1.fr

### 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)
    }

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