set.seed(123)
x = abs(rnorm(100, 10, 5))

xbar = mean(x)
print( sprintf("cor(x, x^2)= %3.4f; cor((x-xbar), (x-xbar)^2)= %3.4f", cor(x, x^2), cor(x-xbar, (x-xbar)^2)) )

#postscript("../../WriteUp/Graphics/Chapter2/ex_2_17_plot.eps", onefile=FALSE, horizontal=FALSE)
par(mfrow=c(1,2)) 
plot( x, x^2 )
grid()
plot( x-xbar, (x-xbar)^2 )
grid()
par(mfrow=c(1,1))
#dev.off()