R: Exact global Moran's I test

lm.morantest.exact {spdep} | R Documentation

## Exact global Moran's I test

### Description

The function implements Tiefelsdorf's exact global Moran's I test.

### Usage

    lm.morantest.exact(model, listw, zero.policy = NULL, alternative = "greater",
     spChk = NULL, resfun = weighted.residuals, zero.tol = 1e-07, Omega=NULL,
     save.M=NULL, save.U=NULL, useTP=FALSE, truncErr=1e-6, zeroTreat=0.1)
    ## S3 method for class 'moranex'
    print(x, ...)

### Arguments

`model` | an object of class `lm` returned by `lm`; weights may be specified in the `lm` fit, but offsets should not be used
`listw` | a `listw` object created for example by `nb2listw`
`zero.policy` | default NULL, use global option value; if TRUE assign zero to the lagged value of zones without neighbours, if FALSE assign NA
`alternative` | a character string specifying the alternative hypothesis, must be one of greater (default), less or two.sided.
`spChk` | should the data vector names be checked against the spatial objects for identity integrity, TRUE, or FALSE, default NULL to use `get.spChkOption()`
`resfun` | default: weighted.residuals; the function to be used to extract residuals from the `lm` object, may be `residuals`, `weighted.residuals`, `rstandard`, or `rstudent`
`zero.tol` | tolerance used to find eigenvalues close to absolute zero
`Omega` | A SAR process matrix may be passed in to test an alternative hypothesis, for example `Omega <- invIrW(listw, rho=0.1); Omega <- tcrossprod(Omega)`, `chol()` is taken internally
`save.M` | return the full M matrix for use in `spdep:::exactMoranAlt`
`save.U` | return the full U matrix for use in `spdep:::exactMoranAlt`
`useTP` | default FALSE, if TRUE, use truncation point in integration rather than upper=Inf, see Tiefelsdorf (2000), eq. 6.7, p.69
`truncErr` | when useTP=TRUE, pass truncation error to truncation point function
`zeroTreat` | when useTP=TRUE, pass zero adjustment to truncation point function
`x` | a moranex object
`...` | arguments to be passed through

### Value

A list of class `moranex` with the following components:

`statistic` | the value of the saddlepoint approximation of the standard deviate of global Moran's I.
`p.value` | the p-value of the test.
`estimate` | the value of the observed global Moran's I.
`method` | a character string giving the method used.
`alternative` | a character string describing the alternative hypothesis.
`gamma` | eigenvalues (excluding zero values)
`oType` | usually set to "E"
`data.name` | a character string giving the name(s) of the data.
`df` | degrees of freedom

### Author(s)

Markus Reder and Roger Bivand

### References

Roger Bivand, Werner G. Müller and Markus Reder (2009) "Power calculations for global and local Moran's I." Computational Statistics \& Data Analysis 53, 2859-2872.

### See Also

`lm.morantest.sad`

### Examples

    require(maptools)
    eire <- readShapePoly(system.file("etc/shapes/eire.shp", package="spdep")[1],
      ID="names", proj4string=CRS("+proj=utm +zone=30 +ellps=airy +units=km"))
    eire.nb <- poly2nb(eire)
    #data(eire)
    e.lm <- lm(OWNCONS ~ ROADACC, data=eire)
    lm.morantest(e.lm, nb2listw(eire.nb))
    lm.morantest.sad(e.lm, nb2listw(eire.nb))
    lm.morantest.exact(e.lm, nb2listw(eire.nb))
    lm.morantest.exact(e.lm, nb2listw(eire.nb), useTP=TRUE)

[Package spdep version 0.6-13 Index]