Spatial lag of a numeric vector

Using a listw sparse representation of a spatial weights matrix, compute the lag vector \(V x\)

# S3 method for listw
lag(x, var, zero.policy=attr(listw, "zero.policy"), NAOK=FALSE, ...)

Arguments

x

a listw object created for example by nb2listw

var

a numeric vector the same length as the neighbours list in listw

zero.policy

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

NAOK

If 'FALSE', the presence of 'NA' values is regarded as an error; if 'TRUE' then any 'NA' or 'NaN' or 'Inf' values in var are represented as an NA lagged value.

...

additional arguments

Value

a numeric vector the same length as var

Author

Roger Bivand Roger.Bivand@nhh.no

See also

nb2listw

Examples

data(oldcol)
Vx <- lag.listw(nb2listw(COL.nb, style="W"), COL.OLD$CRIME)
plot(Vx, COL.OLD$CRIME)

plot(ecdf(COL.OLD$CRIME))
plot(ecdf(Vx), add=TRUE, col.points="red", col.hor="red")

is.na(COL.OLD$CRIME[5]) <- TRUE
VxNA <- lag.listw(nb2listw(COL.nb, style="W"), COL.OLD$CRIME, NAOK=TRUE)
#> Warning: NAs in lagged values