spdep (version 0.5-74)

lee: Compute Lee's statistic

Description

A simple function to compute Lee's L statistic for bivariate spatial data;$$L(x,y)=\frac{n}{\sum _{i=1}^n(\sum _{j=1}^n{w}_{ij}{)}^2}\frac{\sum _{i=1}^n(\sum _{j=1}^n{w}_{ij}(x_i-\overline{x}))((\sum _{j=1}^n{w}_{ij}(y_j-\overline{y}))}{\sqrt{\sum _{i=1}^n(x_i-\overline{x}{)}^2}\sqrt{\sum _{i=1}^n(y_i-\overline{y}{)}^2}}$$

Usage

lee(x, y, listw, n, S2, zero.policy=NULL, NAOK=FALSE)

Arguments

x

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

y

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

S2

Sum of squared sum of weights by rows.

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
• L
  Lee's L statistic
• local L
  Lee's local L statistic

encoding

latin1

References

Lee (2001). Developing a bivariate spatial association measure: An integration of Pearson's r and Moran's I. J Geograph Syst 3: 369-385

See Also

lee.mc

Examples

data(boston)
lw<-nb2listw(boston.soi)

x<-boston.c$CMEDV
y<-boston.c$CRIM
z<-boston.c$RAD

Lxy<-lee(x, y, lw, length(x), zero.policy=TRUE)
Lxz<-lee(x, z, lw, length(x), zero.policy=TRUE)