eigenw {spdep} | R Documentation

## Spatial weights matrix eigenvalues

### Description

The function returns a numeric vector of eigenvalues of the weights matrix generated from the spatial weights object `listw`. The eigenvalues are used to speed the computation of the Jacobian in spatial SAR model estimation:

log(det[I - rho W]) = logprod_{i=1}^{n}(1 - rho λ_i)

where $W$ is the n by n spatial weights matrix, and $λ_i$ are the eigenvalues of $W$.

### Usage

    eigenw(listw, quiet=TRUE)

### Arguments

`listw` | a `listw` object created for example by `nb2listw`
`quiet` | set to FALSE for short summary

### Value

a numeric vector of eigenvalues of the weights matrix generated from the spatial weights object `listw`.

### Author(s)

Roger Bivand Roger.Bivand@nhh.no

### References

Cliff, A. D., Ord, J. K. 1981 Spatial processes, Pion, p. 155; Ord, J. K. 1975 Estimation methods for models of spatial interaction, Journal of the American Statistical Association, 70, 120-126.

### See Also

`eigen`,

### Examples

    data(oldcol)
    W.eig <- eigenw(nb2listw(COL.nb, style="W"))
    1/range(W.eig)
    S.eig <- eigenw(nb2listw(COL.nb, style="S"))
    1/range(S.eig)
    B.eig <- eigenw(nb2listw(COL.nb, style="B"))
    1/range(B.eig)

[Package spdep version 0.3-25 Index]