moran {spdep}R Documentation

Compute Moran's I

Description

A simple function to compute Moran's I, called by moran.test and moran.mc;

I = (n sum_i sum_j w_ij (x_i - xbar) (x_j - xbar)) / (S0 sum_i (x_i - xbar)^2)

Usage

moran(x, listw, n, S0, zero.policy=FALSE, NAOK=FALSE)

Arguments

x a numeric vector the same length as the neighbours list in listw
listw a listw object created for example by nb2listw
n number of zones
S0 global sum of weights
zero.policy if TRUE assign zero to the lagged value of zones without neighbours, if FALSE assign NA
NAOK if 'TRUE' then any 'NA' or 'NaN' or 'Inf' values in x are passed on to the foreign function. If 'FALSE', the presence of 'NA' or 'NaN' or 'Inf' values is regarded as an error.

Value

a list of

I Moran's I
K sample kurtosis of x

Author(s)

Roger Bivand Roger.Bivand@nhh.no

References

Cliff, A. D., Ord, J. K. 1981 Spatial processes, Pion, p. 17.

See Also

moran.test, moran.mc

Examples

data(oldcol)
col.W <- nb2listw(COL.nb, style="W")
crime <- spNamedVec("CRIME", COL.OLD)
str(moran(crime, col.W, length(COL.nb), Szero(col.W)))
is.na(crime) <- sample(1:length(crime), 10)
str(moran(crime, col.W, length(COL.nb), Szero(col.W), NAOK=TRUE))

[Package spdep version 0.3-12 Index]