moran: Compute Moran's I

Description Usage Arguments Value Author(s) References See Also Examples

View source: R/moran.R

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

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moran(x, listw, n, S0, zero.policy=NULL, 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

default NULL, use global option value; 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 [email protected]

References

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

See Also

moran.test, moran.mc

Examples

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data(oldcol)
col.W <- nb2listw(COL.nb, style="W")
crime <- COL.OLD$CRIME
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))

Example output

Loading required package: sp
Loading required package: Matrix
List of 2
 $ I: num 0.511
 $ K: num 2.23
List of 2
 $ I: num 0.222
 $ K: num 2.77
Warning message:
In lag.listw(listw, z, zero.policy = zero.policy, NAOK = NAOK) :
  NAs in lagged values

spdep documentation built on Nov. 21, 2018, 5:05 p.m.