lm.morantest.exact: Exact global Moran's I test

In spdep: Spatial Dependence: Weighting Schemes, Statistics

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 = attr(listw, "zero.policy"),
 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 attr(listw, "zero.policy") as set when listw was created, if attribute not set, 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 exact 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

eire <- st_read(system.file("shapes/eire.gpkg", package="spData")[1])
row.names(eire) <- as.character(eire$names)
eire.nb <- poly2nb(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)

spdep documentation built on Sept. 13, 2024, 5:07 p.m.