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 = FALSE, 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 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

See Also

lm.morantest.sad

Examples

eire <- readShapePoly(system.file("etc/shapes/eire.shp", package="spdep")[1],
  ID="names", proj4string=CRS("+proj=utm +zone=30 +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 0.4-34 Index]