R: Compute Moran's I

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=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 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 <- 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))

[Package spdep version 1.2-2 Index]