moran.Rd
A simple function to compute Moran's I, called by moran.test
and moran.mc
;
$$I = \frac{n}{\sum_{i=1}^{n}\sum_{j=1}^{n}w_{ij}}
\frac{\sum_{i=1}^{n}\sum_{j=1}^{n}w_{ij}(x_i-\bar{x})(x_j-\bar{x})}{\sum_{i=1}^{n}(x_i - \bar{x})^2}
$$
moran(x, listw, n, S0, zero.policy=attr(listw, "zero.policy"), NAOK=FALSE)
a numeric vector the same length as the neighbours list in listw
a listw
object created for example by nb2listw
number of zones
global sum of weights
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
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.
a list of
Moran's I
sample kurtosis of x
Cliff, A. D., Ord, J. K. 1981 Spatial processes, Pion, p. 17.
data(oldcol)
col.W <- nb2listw(COL.nb, style="W")
crime <- COL.OLD$CRIME
str(moran(crime, col.W, length(COL.nb), Szero(col.W)))
#> List of 2
#> $ I: num 0.511
#> $ K: num 2.23
is.na(crime) <- sample(1:length(crime), 10)
str(moran(crime, col.W, length(COL.nb), Szero(col.W), NAOK=TRUE))
#> Warning: NAs in lagged values
#> List of 2
#> $ I: num 0.142
#> $ K: num 2.82