data(environmental,package="lattice")
nam <- dimnames(environmental)[[2]]
pdf("lowess6.pdf",width=10,height=10)
par(mfrow=c(4,4))
par(mar=c(4,4,1,1))
for (j in 1:4){
for (i in 1:4){
if (i==j){plot(environmental[,c(i,j)],xlab=nam[i],ylab=nam[j],cex.lab=1.2,type="n")}
else {
plot(environmental[,c(i,j)],cex.lab=1.2)
lines(sort(environmental[,i]),lowess(environmental[,i],environmental[,j])$y)
lines(lowess(environmental[,j],environmental[,i])$y,sort(environmental[,j]),lty=2,lwd=2)
}
}
}
dev.off()